Preguntes més freqüents

Generally it is impossible to have perfect anonymity, even with Tor. Though there are some things you can practice to improve your anonymity while using Tor and offline.

Use Tor Browser and software specifically configured for Tor

Tor does not protect all of your computer's Internet traffic when you run it. Tor only protects applications that are properly configured to send their Internet traffic through Tor.

Web browsing:

File sharing:

Control what information you provide through web forms

If you visit a website using Tor Browser, they don't know who you are or your true location. Unfortunately many sites ask for more personal information than they need through web forms. If you sign in to that website, they still don't know your location but they know who you are. Further, if you provide: name, email, address, phone number, or any other personal information, you are no longer anonymous to that website. The best defense is to be vigilant and extremely cautious when filling out web forms.

Don't torrent over Tor

Torrent file-sharing applications have been observed to ignore proxy settings and make direct connections even when they are told to use Tor. Even if your torrent application connects only through Tor, you will often send out your real IP address in the tracker GET request, because that's how torrents work. Not only do you deanonymize your torrent traffic and your other simultaneous Tor web traffic this way, you also slow down the entire Tor network for everyone else.

Don't enable or install browser plugins

El Navegador Tor blocarà connectors com ara Flash, RealPlayer, Quicktime i d'altres: els podrien manipular perquè revelin la vostra adreça IP. Similarly, we do not recommend installing additional addons or plugins into Tor Browser, as these may bypass Tor or otherwise harm your anonymity and privacy.

Use HTTPS versions of websites

Tor will encrypt your traffic to and within the Tor network, but the encryption of your traffic to the final destination website depends on that website. To help ensure private encryption to websites, Tor Browser includes HTTPS Everywhere to force the use of HTTPS encryption with major websites that support it. However, you should still watch the browser URL bar to ensure that websites you provide sensitive information to display a padlock or onion icon in the address bar, include https:// in the URL, and display the proper expected name for the website. Also see EFF's interactive graphic explaining how Tor and HTTPS relate.

Don't open documents downloaded through Tor while online

Tor Browser will warn you before automatically opening documents that are handled by external applications. DO NOT IGNORE THIS WARNING. You should be very careful when downloading documents via Tor (especially DOC and PDF files, unless you use the PDF viewer that's built into Tor Browser) as these documents can contain Internet resources that will be downloaded outside of Tor by the application that opens them. This will reveal your non-Tor IP address. If you must work with files downloaded via Tor, we strongly recommend either using a disconnected computer, or using dangerzone to create safe PDF files that you can open. Under no circumstances is it safe to use BitTorrent and Tor together, however.

Use bridges and/or find company

Tor tries to prevent attackers from learning what destination websites you connect to. However, by default, it does not prevent somebody watching your Internet traffic from learning that you're using Tor. If this matters to you, you can reduce this risk by configuring Tor to use a bridge rather than connecting directly to the Tor network. Ultimately the best protection is a social approach: the more Tor users there are near you and the more diverse their interests, the less dangerous it will be that you are one of them. Convince other people to use Tor, too!

Be smart and learn more. Understand what Tor does and does not offer. This list of pitfalls isn't complete, and we need your help identifying and documenting all the issues.

Sure! We have a list of organizations that run Tor relays that are happy to turn your donations into better speed and anonymity for the Tor network.

These organizations are not the same as The Tor Project, Inc, but we consider that a good thing. They're run by nice people who are part of the Tor community.

Note that there can be a tradeoff here between anonymity and performance. The Tor network's anonymity comes in part from diversity, so if you are in a position to run your own relay, you will be improving Tor's anonymity more than by donating. At the same time though, economies of scale for bandwidth mean that combining many small donations into several larger relays is more efficient at improving network performance. Improving anonymity and improving performance are both worthwhile goals, so however you can help is great!

En termes generals, no recomanem utilitzar una VPN amb Tor llevat que sigueu un usuari avançat que sàpiga com configurar-los d'una manera que no comprometi la vostra privadesa.

Podeu trobar informació més detallada sobre Tor + VPN al nostre wiki.

Tor Browser is currently available on Windows, Linux and macOS.

There is a version of Tor Browser for Android and The Guardian Project also provides the Orbot app to route other apps on your Android device over the Tor network.

Encara no hi ha una versió oficial del Tor per a l'iOS, tot i que recomanem l'Onion Browser.

Desaconsellem encaridament que instal·leu complements nous en el Navegador Tor, ja que poden comprometre la vostra privadesa i seguretat.

Instal·lar complements podria afectar el Navegador Tor en maneres imprevisibles i fer única la vostra empremta digital. Si la vostra còpia del Navegador Tor té una empremta única, les vostres activitats poden deixar de ser anònimes i es poden rastrejar, encara que estigueu utilitzant el Navegador Tor.

Bàsicament, la configuració i funcions de cada navegador creen el que es coneix com a «empremta del navegador». La majoria dels navegadors creen sense voler una empremta única per a cada usuari que es pot rastrejar a través de la internet. Tor Browser is specifically engineered to have a nearly identical (we're not perfect!) fingerprint across its users. Això significa que cada usuari del Navegador Tor sembla com qualsevol altre usuari d'aquest, fent que rastrejar un usuari individual sigui difícil.

També hi ha una probabilitat alta de què un complement nou incrementi la superfície d'atac del Navegador Tor. Això podria permetre que es filtressin dades sensibles o permetre que un atacant infectés el Navegador Tor. El mateix complement podria estar dissenyat de manera maliciosa per a espiar-vos.

Tor Browser ja ve instal·lat amb dos complements: HTTPS Everywhere i NoScript, i afegir-ne qualsevol altre podria fer perdre l'anonimat

Want to learn more about browser fingerprinting? Here's an article on The Tor Blog all about it.

El Navegador Tor pot, per descomptat, ajudar els usuaris a accedir al vostre lloc web des d'ubicacions on estigui blocat. Normalment, només cal baixar el Navegador Tor i utilitzar-lo per a navegar per la pàgina blocada per a poder accedir-hi. En llocs on hi ha una gran censura, tenim disponibles diverses opcions d’elusió de la censura, incloent-hi transports connectables.

Per a obtenir més informació, consulteu la secció de censura del manual d’usuari del Navegador Tor.

El Navegador Tor evita que la gent conegui els llocs web que visiteu. Algunes entitats, com ara el vostre proveïdor de serveis d’Internet (ISP), podrien veure que esteu utilitzant Tor, però no sabran on aneu quan ho feu.

Quant al Tor

Internet communication is based on a store-and-forward model that can be understood in analogy to postal mail: Data is transmitted in blocks called IP datagrams or packets. Every packet includes a source IP address (of the sender) and a destination IP address (of the receiver), just as ordinary letters contain postal addresses of sender and receiver. The way from sender to receiver involves multiple hops of routers, where each router inspects the destination IP address and forwards the packet closer to its destination. Thus, every router between sender and receiver learns that the sender is communicating with the receiver. In particular, your local ISP is in the position to build a complete profile of your Internet usage. In addition, every server in the Internet that can see any of the packets can profile your behavior.

The aim of Tor is to improve your privacy by sending your traffic through a series of proxies. Your communication is encrypted in multiple layers and routed via multiple hops through the Tor network to the final receiver. More details on this process can be found in this visualization. Note that all your local ISP can observe now is that you are communicating with Tor nodes. Similarly, servers in the Internet just see that they are being contacted by Tor nodes.

Generally speaking, Tor aims to solve three privacy problems:

First, Tor prevents websites and other services from learning your location, which they can use to build databases about your habits and interests. With Tor, your Internet connections don't give you away by default -- now you can have the ability to choose, for each connection, how much information to reveal.

Second, Tor prevents people watching your traffic locally (such as your ISP or someone with access to your home wifi or router) from learning what information you're fetching and where you're fetching it from. It also stops them from deciding what you're allowed to learn and publish -- if you can get to any part of the Tor network, you can reach any site on the Internet.

Third, Tor routes your connection through more than one Tor relay so no single relay can learn what you're up to. Because these relays are run by different individuals or organizations, distributing trust provides more security than the old one hop proxy approach.

Note, however, that there are situations where Tor fails to solve these privacy problems entirely: see the entry below on remaining attacks.

As mentioned above, it is possible for an observer who can view both you and either the destination website or your Tor exit node to correlate timings of your traffic as it enters the Tor network and also as it exits. Tor does not defend against such a threat model.

In a more limited sense, note that if a censor or law enforcement agency has the ability to obtain specific observation of parts of the network, it is possible for them to verify a suspicion that you talk regularly to your friend by observing traffic at both ends and correlating the timing of only that traffic. Again, this is only useful to verify that parties already suspected of communicating with one another are doing so. In most countries, the suspicion required to obtain a warrant already carries more weight than timing correlation would provide.

Furthermore, since Tor reuses circuits for multiple TCP connections, it is possible to associate non anonymous and anonymous traffic at a given exit node, so be careful about what applications you run concurrently over Tor. Perhaps even run separate Tor clients for these applications.

El nom «Tor» pot fer referència a uns quants components diferents.

Tor is a program you can run on your computer that helps keep you safe on the Internet. It protects you by bouncing your communications around a distributed network of relays run by volunteers all around the world: it prevents somebody watching your Internet connection from learning what sites you visit, and it prevents the sites you visit from learning your physical location. This set of volunteer relays is called the Tor network.

The way most people use Tor is with Tor Browser, which is a version of Firefox that fixes many privacy issues. You can read more about Tor on our about page.

The Tor Project is a non-profit (charity) organization that maintains and develops the Tor software.

Tor is the onion routing network. When we were starting the new next-generation design and implementation of onion routing in 2001-2002, we would tell people we were working on onion routing, and they would say "Neat. Which one?" Even if onion routing has become a standard household term, Tor was born out of the actual onion routing project run by the Naval Research Lab.

(It's also got a fine meaning in German and Turkish.)

Note: even though it originally came from an acronym, Tor is not spelled "TOR". Only the first letter is capitalized. In fact, we can usually spot people who haven't read any of our website (and have instead learned everything they know about Tor from news articles) by the fact that they spell it wrong.

No, no ho fa. Cal que utilitzeu un altre programa que comprengui eixa aplicació i el seu protocol, i que conegui com netejar o «agranar» les dades que hi envia. El Navegador Tor prova de mantenir les dades a escala d'aplicació, com ara la cadena d'agent d'usuari, uniforme per a tots els usuaris. Tor Browser can't do anything about the text that you type into forms, though.

Un servidor intermediari típic configura un servidor arreu a internet i us permet utilitzar-lo per a reconduir el vostre trànsit. Això crea una arquitectura simple i fàcil de mantenir. Tots els usuaris entren i se'n van a través del mateix servidor. El proveïdor podria cobrar per utilitzar el servidor, o finançar els seus costs mitjançant publicitat al servidor. Amb la configuració més simple, no heu d'instal·lar res. Només cal que dirigiu el navegador al servidor intermediari. Els servidors intermediaris simples són solucions adequades si no voleu protegir la vostra privadesa i anonimat en línia, i confieu que el proveïdor no faci res dolent. Alguns servidors simples utilitzen SSL per a fer segura la vostra connexió, i això us protegeix contra tafaners locals, com els que podríeu trobar en un cafè amb WiFi gratis.

Els servidors intermediaris simples també creen un punt de fallada únic. El proveïdor coneix qui sou i on navegueu en internet. Poden veure el vostre transit mentre passa a través del seu servidor. De vegades, inclús poden veure el vostre trànsit xifrat mentre l'envien al lloc web del vostre banc o comerç electrònic. Heu de confiar que el proveïdor no està vigilant el vostre trànsit, injectant els seus anuncis en el flux de dades, o enregistrant els vostres detalls personals.

El Tor passa el vostre trànsit a través de, com a mínim, 3 servidors diferents abans d'enviar-lo al seu destí. Ningú que vigili la vostra connexió a internet pot modificar ni llegir el que esteu enviat a la xarxa Tor, perquè hi ha una capa separada de xifratge per a cadascun dels tres relés. El vostre trànsit es xifra entre el client Tor (en el vostre equip) i on surt, en algun altre lloc del planeta.

I el primer servidor no veu on sóc?

Possiblement. Un primer servidor dolent pot veure que des del vostre equip arriba trànsit Tor xifrat. Tot i això, no sap qui sou i què esteu fent en la xarxa Tor. Gairebé no veu «Aquesta IP està utilitzant el Tor». De tota manera, la protecció fa que aquest servidor no pugui esbrinar ni qui sou ni on aneu en la internet.

Pot veure el meu trànsit el tercer servidor?

Possiblement. Un tercer servidor dolent pot veure el trànsit que envieu al Tor. Però no sabrà qui l'ha enviat. Si utilitzeu algun xifratge (com ara HTTPS), només sabrà quin és el seu destí. See this visualization of Tor and HTTPS to understand how Tor and HTTPS interact.

Sí.

El Tor és programari lliure. Això significa que us donem els drets per a distribuir el programari Tor, tant modificat com sense modificar, tant de pagament com gratis. No cal que ens demaneu cap permís en concret.

Tot i això, si voleu redistribuir el Tor, haureu de seguir la nostra LLICÈNCIA. En resum, això significa que cal que inclogueu el nostre fitxer de LLICÈNCIA junt amb qualsevol part del programari Tor que distribuïu.

De tota manera, la majoria dels qui ens pregunten sobre això no volen distribuir només el Tor. Volen distribuir el Navegador Tor. Això inclou el Firefox Extended Support Release, i els complements NoScript i HTTPS-Everywhere. També cal que seguiu la llicència d'aquests programes. Ambdós complements del Firefox es distribueixen sota la GNU General Public License; en canvi, el Firefox ESR s'allibera sota la Mozilla Public License. La forma més senzilla d'obeir les seves llicències és incloure el codi font d'eixos programes a tots els llocs on inclogueu els mateixos programes.

També haureu d'assegurar-vos de no confondre els vostres lectors sobre què és el Tor, qui el fa, i quines propietats proporciona (i quines no). Mireu les nostres PMF sobre la marca per a més detalls.

Hi ha una gran quantitat d'altres programes que podeu utilitzar amb el Tor, però no hem investigat prou, a un nivell detallat, els problemes d'anonimat de tots ells per a poder recomanar una configuració segura. La nostra wiki té una llista d'instruccions mantinguda per la comunitat per a Torificar aplicacions específiques. Please add to this list and help us keep it accurate!

La majoria de gent utilitza el Navegador Tor, que inclou tot el que necessiteu per a navegar per la web amb seguretat utilitzant el Tor. Using Tor with other browsers is dangerous and not recommended.

No hi ha cap porta del darrere en el Tor.

Coneixem uns quants advocats molt intel·ligents que diuen que és molt poc probable que ningú no ens faci afegir-ne cap en la nostra jurisdicció (EUA). Si ho intenten, els plantarem cara, i (els advocats diuen que) probablement guanyarem.

Mai no posarem cap porta del darrere en el Tor. Pensem que posar-li una porta del darrere al Tor seria tremendament irresponsable de cara als nostres usuaris, i un precedent dolent per a la seguretat del programari en general. If we ever put a deliberate backdoor in our security software, it would ruin our professional reputation. Nobody would trust our software ever again - for excellent reasons!

Però, dit això, hi ha multitud d'atacs subtils que la gent podria intentar. Algú podria fer-se passar per nosaltres, o colar-se en els nostres ordinadors, o alguna cosa similar. El Tor és de codi obert, i sempre hauríeu de comprovar el codi (o almenys les diferències amb la versió anterior) si hi noteu alguna cosa sospitosa. If we (or the distributors that gave you Tor) don't give you access to the source code, that's a sure sign something funny might be going on. You should also check the PGP signatures on the releases, to make sure nobody messed with the distribution sites.

A més d'això, podrien haver-hi errors accidentals en el Tor que podrien afectar el vostre anonimat. Trobem i corregim periòdicament errors relacionats amb l'anonimat, així que assegureu-vos que teniu actualitzada la vostra versió del Tor.

Tor (like all current practical low-latency anonymity designs) fails when the attacker can see both ends of the communications channel. For example, suppose the attacker controls or watches the Tor relay you choose to enter the network, and also controls or watches the website you visit. In this case, the research community knows no practical low-latency design that can reliably stop the attacker from correlating volume and timing information on the two sides.

So, what should we do? Suppose the attacker controls, or can observe, C relays. Suppose there are N relays total. If you select new entry and exit relays each time you use the network, the attacker will be able to correlate all traffic you send with probability around (c/n)2. But profiling is, for most users, as bad as being traced all the time: they want to do something often without an attacker noticing, and the attacker noticing once is as bad as the attacker noticing more often. Thus, choosing many random entries and exits gives the user no chance of escaping profiling by this kind of attacker.

The solution is "entry guards": each Tor client selects a few relays at random to use as entry points, and uses only those relays for their first hop. If those relays are not controlled or observed, the attacker can't win, ever, and the user is secure. If those relays are observed or controlled by the attacker, the attacker sees a larger fraction of the user's traffic - but still the user is no more profiled than before. Thus, the user has some chance (on the order of (n-c)/n) of avoiding profiling, whereas they had none before.

You can read more at An Analysis of the Degradation of Anonymous Protocols, Defending Anonymous Communication Against Passive Logging Attacks, and especially Locating Hidden Servers.

Restricting your entry nodes may also help against attackers who want to run a few Tor nodes and easily enumerate all of the Tor user IP addresses. (Even though they can't learn what destinations the users are talking to, they still might be able to do bad things with just a list of users.) However, that feature won't really become useful until we move to a "directory guard" design as well.

Tor uses a variety of different keys, with three goals in mind: 1) encryption to ensure privacy of data within the Tor network, 2) authentication so clients know they're talking to the relays they meant to talk to, and 3) signatures to make sure all clients know the same set of relays.

Encryption: first, all connections in Tor use TLS link encryption, so observers can't look inside to see which circuit a given cell is intended for. Further, the Tor client establishes an ephemeral encryption key with each relay in the circuit; these extra layers of encryption mean that only the exit relay can read the cells. Both sides discard the circuit key when the circuit ends, so logging traffic and then breaking into the relay to discover the key won't work.

Authentication: Every Tor relay has a public decryption key called the "onion key". Each relay rotates its onion key once a week. When the Tor client establishes circuits, at each step it demands that the Tor relay prove knowledge of its onion key. That way the first node in the path can't just spoof the rest of the path. Because the Tor client chooses the path, it can make sure to get Tor's "distributed trust" property: no single relay in the path can know about both the client and what the client is doing.

Coordination: How do clients know what the relays are, and how do they know that they have the right keys for them? Each relay has a long-term public signing key called the "identity key". Each directory authority additionally has a "directory signing key". The directory authorities provide a signed list of all the known relays, and in that list are a set of certificates from each relay (self-signed by their identity key) specifying their keys, locations, exit policies, and so on. So unless the adversary can control a majority of the directory authorities (as of 2021 there are 10 directory authorities), they can't trick the Tor client into using other Tor relays.

How do clients know what the directory authorities are?

The Tor software comes with a built-in list of location and public key for each directory authority. So the only way to trick users into using a fake Tor network is to give them a specially modified version of the software.

How do users know they've got the right software?

When we distribute the source code or a package, we digitally sign it with GNU Privacy Guard. See the instructions on how to check Tor Browser's signature.

In order to be certain that it's really signed by us, you need to have met us in person and gotten a copy of our GPG key fingerprint, or you need to know somebody who has. If you're concerned about an attack on this level, we recommend you get involved with the security community and start meeting people.

Tor will reuse the same circuit for new TCP streams for 10 minutes, as long as the circuit is working fine. (If the circuit fails, Tor will switch to a new circuit immediately.)

But note that a single TCP stream (e.g. a long IRC connection) will stay on the same circuit forever. We don't rotate individual streams from one circuit to the next. Otherwise, an adversary with a partial view of the network would be given many chances over time to link you to your destination, rather than just one chance.

Navegador Tor

La signatura digital és un procés que assegura que un paquet determinat ha estat generat pels seus desenvolupadors i no ha estat alterat. Below we explain why it is important and how to verify that the Tor Browser you download is the one we have created and has not been modified by some attacker.

Each file on our download page is accompanied by a file labelled "signature" with the same name as the package and the extension ".asc". These .asc files are OpenPGP signatures. Això us permet verificar que el fitxer que esteu baixant és exactament el que heu demanat. This will vary by web browser, but generally you can download this file by right-clicking the "signature" link and selecting the "save file as" option.

For example, torbrowser-install-win64-9.0_en-US.exe is accompanied by torbrowser-install-win64-9.0_en-US.exe.asc. These are example file names and will not exactly match the file names that you download.

We now show how you can verify the downloaded file's digital signature on different operating systems. Please notice that a signature is dated the moment the package has been signed. Therefore every time a new file is uploaded a new signature is generated with a different date. As long as you have verified the signature you should not worry that the reported date may vary.

Installing GnuPG

First of all you need to have GnuPG installed before you can verify signatures.

For Windows users:

If you run Windows, download Gpg4win and run its installer.

In order to verify the signature you will need to type a few commands in windows command-line, cmd.exe.

Per a usuaris macOS:

If you are using macOS, you can install GPGTools.

In order to verify the signature you will need to type a few commands in the Terminal (under "Applications").

For GNU/Linux users:

If you are using GNU/Linux, then you probably already have GnuPG in your system, as most GNU/Linux distributions come with it preinstalled.

In order to verify the signature you will need to type a few commands in a terminal window. How to do this will vary depending on your distribution.

Fetching the Tor Developers key

The Tor Browser team signs Tor Browser releases. Import the Tor Browser Developers signing key (0xEF6E286DDA85EA2A4BA7DE684E2C6E8793298290):

‪# gpg --auto-key-locate nodefault,wkd --locate-keys torbrowser@torproject.org

This should show you something like:

gpg: key 4E2C6E8793298290: public key "Tor Browser Developers (signing key) <torbrowser@torproject.org>" imported
gpg: Total number processed: 1
gpg:               imported: 1
pub   rsa4096 2014-12-15 [C] [expires: 2025-07-21]
      EF6E286DDA85EA2A4BA7DE684E2C6E8793298290
uid           [ unknown] Tor Browser Developers (signing key) <torbrowser@torproject.org>
sub   rsa4096 2018-05-26 [S] [expires: 2020-12-19]

If you get an error message, something has gone wrong and you cannot continue until you've figured out why this didn't work. You might be able to import the key using the Workaround (using a public key) section instead.

After importing the key, you can save it to a file (identifying it by its fingerprint here):

gpg --output ./tor.keyring --export 0xEF6E286DDA85EA2A4BA7DE684E2C6E8793298290

This command results in the key being saved to a file found at the path ./tor.keyring, i.e. in the current directory. If ./tor.keyring doesn't exist after running this command, something has gone wrong and you cannot continue until you've figured out why this didn't work.

Verifying the signature

To verify the signature of the package you downloaded, you will need to download the corresponding ".asc" signature file as well as the installer file itself, and verify it with a command that asks GnuPG to verify the file that you downloaded.

The examples below assume that you downloaded these two files to your "Downloads" folder. Note that these commands use example file names and yours will be different: you will have downloaded a different version than 9.0 and you may not have chosen the English (en-US) version.

For Windows users:

gpgv --keyring .\tor.keyring Downloads\torbrowser-install-win64-9.0_en-US.exe.asc Downloads\torbrowser-install-win64-9.0_en-US.exe

Per a usuaris macOS:

gpgv --keyring ./tor.keyring ~/Downloads/TorBrowser-9.0-osx64_en-US.dmg.asc ~/Downloads/TorBrowser-9.0-osx64_en-US.dmg

For GNU/Linux users (change 64 to 32 if you have the 32-bit package):

gpgv --keyring ./tor.keyring ~/Downloads/tor-browser-linux64-9.0_en-US.tar.xz.asc ~/Downloads/tor-browser-linux64-9.0_en-US.tar.xz

The result of the command should produce something like this:

gpgv: Signature made 07/08/19 04:03:49 Pacific Daylight Time
gpgv:                using RSA key EB774491D9FF06E2
gpgv: Good signature from "Tor Browser Developers (signing key) <torbrowser@torproject.org>"

If you get error messages containing 'No such file or directory', either something went wrong with one of the previous steps, or you forgot that these commands use example file names and yours will be a little different.

Workaround (using a public key)

If you encounter errors you cannot fix, feel free to download and use this public key instead. Alternatively, you may use the following command:

‪# curl -s https://openpgpkey.torproject.org/.well-known/openpgpkey/torproject.org/hu/kounek7zrdx745qydx6p59t9mqjpuhdf |gpg --import -

Tor Browser Developers key is also available on keys.openpgp.org and can be downloaded from https://keys.openpgp.org/vks/v1/by-fingerprint/EF6E286DDA85EA2A4BA7DE684E2C6E8793298290. If you're using MacOS or GNU/Linux, the key can also be fetched by running the following command:
$ gpg --keyserver keys.openpgp.org --search-keys torbrowser@torproject.org

You may also want to learn more about GnuPG.

El fitxer que heu baixat i executat us demana un lloc per la destinació. Si no recordeu quina era aquesta destinació, és probable que sigui la vostra carpeta de baixades o l'escriptori.

The default setting in the Windows installer also creates a shortcut for you on your Desktop, though be aware that you may have accidentally deselected the option to create a shortcut.

Si no podeu trobar-lo en cap d'aquestes carpetes, torneu a baixar-lo i busqueu l'indicador que us demanarà que trieu un directori per baixar-lo. Trieu una ubicació del directori que us recordeu fàcilment i, un cop finalitzada la baixada, heu de veure una carpeta del navegador Tor allà.

Cada vegada que publiquem una versió estable nova del Navegador Tor, escrivim una publicació que detalla les seves funcions i problemes coneguts nous. If you started having issues with your Tor Browser after an update, check out blog.torproject.org for a post on the most recent stable Tor Browser to see if your issue is listed. If your issue is not listed there, please check first Tor Browser's issue tracker and create a GitLab issue about what you're experiencing.

We want everyone to be able to enjoy Tor Browser in their own language. Tor Browser is now available in 36 different languages, and we are working to add more. Want to help us translate? Become a Tor translator!

You can also help us in testing the next languages we will release, by installing and testing Tor Browser Alpha releases.

No, Tor Browser is an open source software and it is free. Any browser forcing you to pay and is claiming to be Tor Browser is fake. To make sure you are downloading the right Tor Browser visit our download page. After downloading, you can make sure that you have the official version of Tor Browser by verifying the signature. If you are not able to access our website, then visit censorship section to get information about alternate way of downloading Tor Browser.

You can report fake Tor Browsers on frontdesk@torproject.org

Tor Browser is currently available on Windows, Linux and macOS.

There is a version of Tor Browser for Android and The Guardian Project also provides the Orbot app to route other apps on your Android device over the Tor network.

Encara no hi ha una versió oficial del Tor per a l'iOS, tot i que recomanem l'Onion Browser.

Malauradament, encara no tenim una versió del navegador Tor per al Chrome OS. You could run Tor Browser for Android on Chrome OS. Note that by using Tor Mobile on Chrome OS, you will view the mobile (not desktop) versions of websites. However, because we have not audited the app in Chrome OS, we don't know if all the privacy features of Tor Browser for Android will work well.

Ho sentim, però actualment no hi ha suport oficial per executar el navegador Tor a *BSD. There is something called the TorBSD project, but their Tor Browser is not officially supported.

L'ús del navegador Tor a vegades pot ser més lent que altres navegadors. The Tor network has over a million daily users, and just over 6000 relays to route all of their traffic, and the load on each server can sometimes cause latency. And, by design, your traffic is bouncing through volunteers' servers in various parts of the world, and some bottlenecks and network latency will always be present. You can help improve the speed of the network by running your own relay, or encouraging others to do so. For the much more in-depth answer, see Roger's blog post on the topic and Tor's Open Research Topics: 2018 edition about Network Performance. Dit això, Tor és molt més ràpid del que era, i és possible que no detecteu canvis en la velocitat d'altres navegadors.

While the names may imply otherwise, 'Incognito mode' and 'private tabs' do not make you anonymous on the Internet. They erase all the information on your machine relating to the browsing session after they are closed, but have no measures in place to hide your activity or digital fingerprint online. This means that an observer can collect your traffic just as easily as any regular browser.

Tor Browser offers all the amnesic features of private tabs while also hiding the source IP, browsing habits and details about a device that can be used to fingerprint activity across the web, allowing for a truly private browsing session that's fully obfuscated from end-to-end.

For more information regarding the limitations of Incognito mode and private tabs, see Mozilla's article on Common Myths about Private Browsing.

There are methods for setting Tor Browser as your default browser, but those methods may not work always or in every operating system. El navegador Tor treballa fort per aïllar-se de la resta del sistema i els passos per fer-ho navegador predeterminat no va en aquesta linea. This means sometimes a website would load in the Tor Browser, and sometimes it would load in another browser. This type of behavior can be dangerous and break anonymity.

Recomanem encarecidament no utilitzar Tor en cap navegador que no sigui el navegador Tor. L'ús de Tor en un altre navegador pot deixar-vos vulnerable sense les proteccions de privadesa del navegador Tor.

Certament, podeu utilitzar un altre navegador mentre feu servir el Navegador Tor. Tanmateix, haureu de saber que les característiques de privadesa del navegador Tor no estaran presents a l'altre navegador. Aneu amb compte quan canvieu entre Tor i un navegador menys segur, ja que podeu utilitzar accidentalment l'altre navegador per a alguna cosa que voleu utilitzar amb Tor.

Si executeu el navegador Tor i un altre navegador alhora, no afectarà el rendiment o les propietats de privadesa de Tor. Tanmateix, tingueu en compte que el vostre altre navegador no manté la privadesa de la vostra activitat i us pot oblidar i utilitzar accidentalment aquest navegador no privat per fer alguna cosa que voleu fer al navegador Tor.

Només el trànsit del navegador Tor s'enviarà a la xarxa Tor. Qualsevol altra aplicació del vostre sistema (inclosos altres navegadors) no tindrà les seves connexions encaminades a la xarxa Tor i no estarà protegida. Han de configurar-se per separat per utilitzar Tor. Si heu d'assegurar-vos que tot el trànsit passarà per la xarxa Tor, feu un cop d'ull al sistema operatiu Tails Live que podreu iniciar a gairebé qualsevol ordinador des d'un llapis USB o un DVD.

We do not recommend running multiple instances of Tor Browser, and doing so may not work as anticipated on many platforms.

El Navegador Tor està construït utilitzant Firefox ESR, de manera que es poden produir errors respecte a Firefox. Assegureu-vos que no hi ha cap altra instància del navegador Tor que ja s'estigui executant i que hagueu extret el navegador Tor en una ubicació que el vostre usuari tingui els permisos correctes. If you are running an anti-virus, please see My antivirus/malware protection is blocking me from accessing Tor Browser, it is common for anti-virus/anti-malware software to cause this type of issue.

El Navegador Tor és una versió modificada de Firefox dissenyada específicament per al seu ús amb Tor. S'ha fet un gran esforç per fer que el navegador Tor, inclòs l'ús de pegats addicionals per millorar la privadesa i la seguretat. Tot i que és tècnicament possible utilitzar Tor amb altres navegadors, podeu obrir-vos a possibles atacs o filtracions d'informació, de manera que us ho desaconsellem molt. Més informació sobre el disseny del navegador Tor.

Bookmarks in the Tor Browser can be exported, imported, backed up, restored as well as imported from another browser. In order to manage your bookmarks in Tor Browser, go to:

  • Hamburger menu >> Library >> Bookmarks >> Show All Bookmarks (below the menu)
  • From the toolbar on the Library window, click Import and Backup

If you wish to export bookmarks

  • Choose Export Bookmarks to HTML
  • In the Export Bookmarks File window that opens, choose a location to save the file, which is named bookmarks.html by default. The desktop is usually a good spot, but any place that is easy to remember will work.
  • Click the Save button. The Export Bookmarks File window will close.
  • Close the Library window.

Your bookmarks are now successfully exported from Tor Browser. The bookmarks HTML file you saved is now ready to be imported into another web browser.

If you wish to import bookmarks

  • Choose Import Bookmarks from HTML
  • Within the Import Bookmarks File window that opens, navigate to the bookmarks HTML file you are importing and select the file.
  • Click the Open button. The Import Bookmarks File window will close.
  • Close the Library window.

The bookmarks in the selected HTML file will be added to your Tor Browser within the Bookmarks Menu directory.

If you wish to backup

  • Choose Backup
  • A new window opens and you have to choose the location to save the file. The file has a .json extension.

If you wish to restore

  • Choose Restore and then select the bookmark file you wish to restore.
  • Click okay to the pop up box that appears and hurray, you just restored your backup bookmark.

Import data from another browser

Bookmarks can be transferred from Firefox to Tor Browser. There are two ways to export and import bookmarks in Firefox: HTML file or JSON file. After exporting the data from the browser, follow the above step to import the bookmark file into your Tor Browser.

Note: Currently, on Tor Browser for Android, there is no good way to export and import bookmarks. Bug #31617

When you have Tor Browser open, you can navigate to the hamburger menu ("≡"), then click on "Preferences", and finally on "Tor" in the side bar. At the bottom of the page, next to the "View the Tor logs" text, click the button "View Logs...". You should see an option to copy the log to your clipboard, which you will be able to paste it into a text editor or an email client.

Alternatively, on GNU/Linux, to view the logs right in the terminal, navigate to the Tor Browser directory and launch the Tor Browser from the command line by running:

./start-tor-browser.desktop --verbose

or to save the logs to a file (default: tor-browser.log)

./start-tor-browser.desktop --log [file]

Tor Browser in its default mode is starting with a content window rounded to a multiple of 200px x 100px to prevent fingerprinting the screen dimensions. The strategy here is to put all users in a couple of buckets to make it harder to single them out. That works so far until users start to resize their windows (e.g. by maximizing them or going into fullscreen mode). Tor Browser ships with a fingerprinting defense for those scenarios as well, which is called Letterboxing, a technique developed by Mozilla and presented in 2019. It works by adding white margins to a browser window so that the window is as close as possible to the desired size while users are still in a couple of screen size buckets that prevent singling them out with the help of screen dimensions.

In simple words, this technique makes groups of users of certain screen sizes and this makes it harder to single out users on basis of screen size, as many users will have same screen size.

letterboxing

El Navegador Tor pot, per descomptat, ajudar els usuaris a accedir al vostre lloc web des d'ubicacions on estigui blocat. Normalment, només cal baixar el Navegador Tor i utilitzar-lo per a navegar per la pàgina blocada per a poder accedir-hi. En llocs on hi ha una gran censura, tenim disponibles diverses opcions d’elusió de la censura, incloent-hi transports connectables.

Per a obtenir més informació, consulteu la secció de censura del manual d’usuari del Navegador Tor.

De vegades, els llocs web bloquen els usuaris de Tor perquè no poden avaluar la diferència entre l'usuari Tor mitjà i el trànsit automatitzat. La millor manera que hem tingut per que els llocs desbloquin els usuaris de Tor és que els usuaris es posin en contacte directament amb els administradors del lloc. Alguna cosa així podria funcionar:

"Hola! He intentat accedir al vostre lloc xyz.com mentre feia servir el Navegador Tor i he descobert que no permet que els usuaris de Tor accedeixin al vostre lloc. Et convido a reconsiderar aquesta decisió; Tor és utilitzat per persones de tot el món per protegir la seva intimitat i lluitar contra la censura. Blocar els usuaris de Tor, probablement blocarà persones en països repressius que vulguin utilitzar una internet lliure, periodistes i investigadors que volen protegir-se de ser descoberts, denunciants, activistes i persones habituals que volen optar per un seguiment invasiu de tercers. Si us plau, prengui una posició forta a favor de la privadesa digital i la llibertat d'internet i permeti als usuaris de Tor accedir a xyz.com.Gràcies"

En el cas dels bancs i altres llocs web sensibles, també és habitual veure blocatge basat en la geografia (si un banc sap que en general accedeix als seus serveis d'un país i, de sobte, es connecta d'un repetidor de sortida a l'altre costat del món, el vostre compte pot estar blocat o suspès).

If you are unable to connect to an onion service, please see I cannot reach X.onion!.

De vegades, els llocs web bloquen els usuaris de Tor perquè no poden avaluar la diferència entre l'usuari Tor mitjà i el trànsit automatitzat. La millor manera que hem tingut per que els llocs desbloquin els usuaris de Tor és que els usuaris es posin en contacte directament amb els administradors del lloc. Alguna cosa així podria funcionar:

"Hola! He intentat accedir al vostre lloc xyz.com mentre feia servir el Navegador Tor i he descobert que no permet que els usuaris de Tor accedeixin al vostre lloc. Et convido a reconsiderar aquesta decisió; Tor és utilitzat per persones de tot el món per protegir la seva intimitat i lluitar contra la censura. Blocar els usuaris de Tor, probablement blocarà persones en països repressius que vulguin utilitzar una internet lliure, periodistes i investigadors que volen protegir-se de ser descoberts, denunciants, activistes i persones habituals que volen optar per un seguiment invasiu de tercers. Si us plau, prengui una posició forta a favor de la privadesa digital i la llibertat d'internet i permeti als usuaris de Tor accedir a xyz.com.Gràcies"

En el cas dels bancs i altres llocs web sensibles, també és habitual veure blocatge basat en la geografia (si un banc sap que en general accedeix als seus serveis d'un país i, de sobte, es connecta d'un repetidor de sortida a l'altre costat del món, el vostre compte pot estar blocat o suspès).

If you are unable to connect to an onion service, please see I cannot reach X.onion!.

El navegador Tor sovint fa que la vostra connexió aparegui com si provingués d'una part completament diferent del món. Alguns llocs web, com ara bancs o proveïdors de correu electrònic, poden interpretar-ho com a signe que el vostre compte s'ha vist compromès i us poden blocar.

L'única manera de resoldre això és seguir el procediment recomanat del lloc per a la recuperació del compte o posar-se en contacte amb els operadors i explicar la situació.

És possible que pugueu evitar aquest escenari si el vostre proveïdor ofereix l'autenticació de doble factor, que és una opció de seguretat molt millor que la reputació basada en IP. Poseu-vos en contacte amb el vostre proveïdor i pregunteu-los si proporcionen 2FA. (autenticació de doble factor)

De vegades, els llocs web amb molt contingut JavaScript poden tenir problemes funcionals sobre el navegador Tor. The simplest fix is to click on the Security icon (the small gray shield at the top-right of the screen), then click "Advanced Security Settings..." Establiu la seguretat a "Estàndard".

Most antivirus or malware protection allows the user to "allowlist" certain processes that would otherwise be blocked. Please open your antivirus or malware protection software and look in the settings for a "allowlist" or something similar. A continuació, s'exclouen els següents processos:

  • Per Windows
    • firefox.exe
    • tor.exe
    • obfs4proxy.exe (si utilitzes ponts)
    • snowflake-client.exe
  • Per a macOS
    • Navegador Tor
    • tor.real
    • obfs4proxy (si utilitzeu ponts)
    • snowflake-client

Finalment, reinicieu el navegador Tor. Això solucionarà els problemes que estigueu experimentant. Tingueu en compte que alguns clients antivirus, com Kaspersky, també poden blocar Tor al nivell de tallafocs.

Some antivirus software will pop up malware and/or vulnerability warnings when Tor Browser is launched. If you downloaded Tor Browser from our main website or used GetTor, and verified it, these are false positives and you have nothing to worry about. Some antiviruses consider that files that have not been seen by a lot of users as suspicious. To make sure that the Tor program you download is the one we have created and has not been modified by some attacker, you can verify Tor Browser's signature. You may also want to permit certain processes to prevent antiviruses from blocking access to Tor Browser.

You might be on a network that is blocking the Tor network, and so you should try using bridges. Some bridges are built in to Tor Browser and requires only a few steps to enable it. When you open Tor Browser for the first time, click "Tor Network Settings". Under the "Bridges" section, select the checkbox "Use a bridge", and choose the "Select a built-in bridge" option. From the dropdown, select whichever pluggable transport you'd like to use. Once you've selected the pluggable transport, scroll up and click "Connect" to save your settings.

Or, if you have Tor Browser running, click on "Preferences" (or "Options" on Windows) in the hamburger menu (≡) and then on "Tor" in the sidebar. In the "Bridges" section, select the checkbox "Use a bridge", and from the option "Select a built-in bridge", choose whichever pluggable transport you'd like to use from the dropdown. Your settings will automatically be saved once you close the tab.

If you need other bridges, you can get them at our Bridges website. For more information about bridges, see the Tor Browser manual.

Un dels problemes més comuns que causa errors de connexió al navegador Tor és un rellotge del sistema incorrecte. Assegureu-vos que el rellotge del sistema i el fus horari estiguin configurats amb precisió. If this doesn't fix the problem, see the Troubleshooting page on the Tor Browser manual.

Sometimes, after you've used Gmail over Tor, Google presents a pop-up notification that your account may have been compromised. The notification window lists a series of IP addresses and locations throughout the world recently used to access your account.

In general, this is a false alarm: Google saw a bunch of logins from different places, as a result of running the service via Tor, and decided it was a good idea to confirm the account was being accessed by its rightful owner.

Even though this may be a byproduct of using the service via Tor, that doesn't mean you can entirely ignore the warning. It is probably a false positive, but it might not be since it is possible for someone to hijack your Google cookie.

Cookie hijacking is possible by either physical access to your computer or by watching your network traffic. In theory, only physical access should compromise your system because Gmail and similar services should only send the cookie over an SSL link. In practice, alas, it's way more complex than that.

And if somebody did steal your Google cookie, they might end up logging in from unusual places (though of course they also might not). So the summary is that since you're using Tor Browser, this security measure that Google uses isn't so useful for you, because it's full of false positives. You'll have to use other approaches, like seeing if anything looks weird on the account, or looking at the timestamps for recent logins and wondering if you actually logged in at those times.

More recently, Gmail users can turn on 2-Step Verification on their accounts to add an extra layer of security.

This is a known and intermittent problem; it does not mean that Google considers Tor to be spyware.

When you use Tor, you are sending queries through exit relays that are also shared by thousands of other users. Tor users typically see this message when many Tor users are querying Google in a short period of time. Google interprets the high volume of traffic from a single IP address (the exit relay you happened to pick) as somebody trying to "crawl" their website, so it slows down traffic from that IP address for a short time.

You can try 'change the circuit for this site' to access the website from a different IP address.

An alternate explanation is that Google tries to detect certain kinds of spyware or viruses that send distinctive queries to Google Search. It notes the IP addresses from which those queries are received (not realizing that they are Tor exit relays), and tries to warn any connections coming from those IP addresses that recent queries indicate an infection.

To our knowledge, Google is not doing anything intentionally specifically to deter or block Tor use. The error message about an infected machine should clear up again after a short time.

Unfortunately, some websites deliver Captchas to Tor users, and we are not able to remove Captchas from websites. The best thing to do in these cases is to contact the website owners, and inform them that their Captchas are preventing users such as yourself from using their services.

Google uses "geolocation" to determine where in the world you are, so it can give you a personalized experience. This includes using the language it thinks you prefer, and it also includes giving you different results on your queries.

If you really want to see Google in English you can click the link that provides that. But we consider this a feature with Tor, not a bug --- the Internet is not flat, and it in fact does look different depending on where you are. This feature reminds people of this fact.

Note that Google search URLs take name/value pairs as arguments and one of those names is "hl". If you set "hl" to "en" then Google will return search results in English regardless of what Google server you have been sent to. The changed link might look like this:

https://encrypted.google.com/search?q=online%20anonymity&hl=en

Another method is to simply use your country code for accessing Google. This can be google.be, google.de, google.us and so on.

Quan utilitzeu el navegador Tor, ningú pot veure els llocs web que visiteu. Tanmateix, el vostre proveïdor de serveis o administradors de xarxa poden veure que esteu connectant a la xarxa Tor, encara que no sabran què feu quan arribeu.

El Navegador Tor evita que la gent conegui els llocs web que visiteu. Algunes entitats, com ara el vostre proveïdor de serveis d’Internet (ISP), podrien veure que esteu utilitzant Tor, però no sabran on aneu quan ho feu.

DuckDuckGo és el motor de cerca predeterminat del navegador Tor. DuckDuckGo no fa el seguiment dels seus usuaris ni emmagatzema dades sobre les cerques dels usuaris. Més informació sobre la política de privadesa de DuckDuckGo.

Amb la publicació del Navegador Tor 6.0.6, vam passar a DuckDuckGo com a motor de cerca principal. For a while now, Disconnect, which was formerly used in Tor Browser, has had no access to Google search results. Since Disconnect is more of a meta search engine, which allows users to choose between different search providers, it fell back to delivering Bing search results, which were basically unacceptable quality-wise. DuckDuckGo does not log, collect or share the user's personal information or their search history, and therefore is best positioned to protect your privacy. Most other search engines store your searches along with other information such as the timestamp, your IP address, and your account information if you are logged in.

EL Navegador Tor té dues maneres de canviar el circuit del repetidor: "Nova identitat" i "Nou circuit Tor per a aquest lloc". Both options are located in the hamburger menu ("≡"). You can also access the New Circuit option inside the site information menu in the URL bar, and the New Identity option by clicking the small sparky broom icon at the top-right of the screen.

Nova Identitat

Aquesta opció és útil si voleu evitar que la vostra activitat posterior del navegador sigui vinculada al que hagueu fet abans.

Si ho seleccioneu, tanqueu totes les pestanyes i finestres, esborreu tota la informació privada, com ara les galetes i l'historial de navegació, i utilitzeu els nous circuits Tor per a totes les connexions.

El navegador Tor us avisarà que tota activitat i baixades s'aturaran, així que teniu això en compte abans de fer clic a «Identitat nova».

Tor Browser Menu

New Tor Circuit for this Site

Aquesta opció és útil si el repetidor de sortida que utilitzeu no pot connectar-se al lloc web que necessiteu o no s'ha carregat correctament. Si ho seleccioneu, es tornarà a carregar la pestanya o la finestra actualment activa en un nou circuit Tor.

Altres pestanyes obertes i finestres del mateix lloc web també usaran el nou circuit una vegada que es tornin a carregar.

Aquesta opció no elimina cap informació privada o desenllaça la vostra activitat, ni afecta les vostres connexions actuals a altres llocs web.

New Circuit for this Site

Executar el navegador Tor no us fa actuar com un repetidor a la xarxa. Això significa que l'ordinador no s'utilitzarà per encaminar el trànsit per a tercers. If you'd like to become a relay, please see our Tor Relay Guide.

Aquest és un comportament normal a Tor El primer repetidor del circuit es diu "guarda d'entrada" o "guarda". Es tracta d'un repetidor ràpid i estable que segueix sent el primer del vostre circuit durant 2-3 mesos per protegir-se contra un atac conegut que trenca l'anonimat. La resta del circuit canvia amb cada nou lloc web que visiteu, i tots junts aquests repetidors proporcionen les proteccions completes de la privacitat de Tor. Per obtenir més informació sobre com funcionen els repetidors de guarda, consulteu aquesta publicació de blog i publicació sobre guàrdies d'entrada.

Modificar la manera en què Tor crea els seus circuits és molt poc recomanable You get the best security that Tor can provide when you leave the route selection to Tor; overriding the entry/exit nodes can compromise your anonymity. Si el resultat que voleu és simplement poder accedir a recursos que només estan disponibles en un sol país, és possible que vulgueu considerar l'ús d'una VPN en lloc d'utilitzar Tor. Tingueu en compte que les VPN no tenen les mateixes propietats de privadesa que Tor, però ajudaran a resoldre alguns problemes de restricció de geolocalització.

WARNING: Do NOT follow random advice instructing you to edit your torrc! Doing so can allow an attacker to compromise your security and anonymity through malicious configuration of your torrc.

Tor uses a text file called torrc that contains configuration instructions for how Tor should behave. The default configuration should work fine for most Tor users (hence the warning above.)

To find your Tor Browser torrc, follow the instructions for your operating system below.

On Windows or Linux:

  • The torrc is in the Tor Browser Data directory at Browser/TorBrowser/Data/Tor inside your Tor Browser directory.

On macOS:

  • The torrc is in the Tor Browser Data directory at ~/Library/Application Support/TorBrowser-Data/Tor.
  • Note the Library folder is hidden on newer versions of macOS. To navigate to this folder in Finder, select "Go to Folder..." in the "Go" menu.
  • Then type "~/Library/Application Support/" in the window and click Go.

Close Tor Browser before you edit your torrc, otherwise Tor Browser may erase your modifications. Some options will have no effect as Tor Browser overrides them with command line options when it starts Tor.

Have a look at the sample torrc file for hints on common configurations. For other configuration options you can use, see the Tor manual page. Remember, all lines beginning with # in torrc are treated as comments and have no effect on Tor's configuration.

Desaconsellem encaridament que instal·leu complements nous en el Navegador Tor, ja que poden comprometre la vostra privadesa i seguretat.

Instal·lar complements podria afectar el Navegador Tor en maneres imprevisibles i fer única la vostra empremta digital. Si la vostra còpia del Navegador Tor té una empremta única, les vostres activitats poden deixar de ser anònimes i es poden rastrejar, encara que estigueu utilitzant el Navegador Tor.

Bàsicament, la configuració i funcions de cada navegador creen el que es coneix com a «empremta del navegador». La majoria dels navegadors creen sense voler una empremta única per a cada usuari que es pot rastrejar a través de la internet. Tor Browser is specifically engineered to have a nearly identical (we're not perfect!) fingerprint across its users. Això significa que cada usuari del Navegador Tor sembla com qualsevol altre usuari d'aquest, fent que rastrejar un usuari individual sigui difícil.

També hi ha una probabilitat alta de què un complement nou incrementi la superfície d'atac del Navegador Tor. Això podria permetre que es filtressin dades sensibles o permetre que un atacant infectés el Navegador Tor. El mateix complement podria estar dissenyat de manera maliciosa per a espiar-vos.

Tor Browser ja ve instal·lat amb dos complements: HTTPS Everywhere i NoScript, i afegir-ne qualsevol altre podria fer perdre l'anonimat

Want to learn more about browser fingerprinting? Here's an article on The Tor Blog all about it.

Flash is disabled in Tor Browser, and we recommend you to not enable it. No creiem que Flash sigui segur d'utilitzar en qualsevol navegador: és una peça de programari molt insegura que pot comprometre la vostra privadesa fàcilment o oferir-vos programari maliciós. Afortunadament, la majoria de llocs web, dispositius i altres navegadors s'estan allunyant de l'ús de Flash.

If you're using Tor Browser, you can set your proxy's address, port, and authentication information in the Network Settings.

If you're using Tor another way, you can set the proxy information in your torrc file. Check out the HTTPSProxy config option in the manual page. If your proxy requires authentication, see the HTTPSProxyAuthenticator option. Example with authentication:

  HTTPSProxy 10.0.0.1:8080
  HTTPSProxyAuthenticator myusername:mypass

We only support Basic auth currently, but if you need NTLM authentication, you may find this post in the archives useful.

For using a SOCKS proxy, see the Socks4Proxy, Socks5Proxy, and related torrc options in the manual page. Using a SOCKS 5 proxy with authentication might look like this:

  Socks5Proxy 10.0.0.1:1080
  Socks5ProxyUsername myuser
  Socks5ProxyPassword mypass

If your proxies only allow you to connect to certain ports, look at the entry on Firewalled clients for how to restrict what ports your Tor will try to access.

If your firewall works by blocking ports, then you can tell Tor to only use the ports when you start your Tor Browser. Or you can add the ports that your firewall permits by adding "FascistFirewall 1" to your torrc configuration file. By default, when you set this Tor assumes that your firewall allows only port 80 and port 443 (HTTP and HTTPS respectively). You can select a different set of ports with the FirewallPorts torrc option. If you want to be more fine-grained with your controls, you can also use the ReachableAddresses config options, e.g.:

ReachableDirAddresses *:80
ReachableORAddresses *:443

Siusplau mira la HTTPS Everywhere FAQ. If you believe this is a Tor Browser issue, please report it on our issue tracker.

By default, your Tor client only listens for applications that connect from localhost. Connections from other computers are refused. If you want to torify applications on different computers than the Tor client, you should edit your torrc to define SocksListenAddress 0.0.0.0 and then restart (or hup) Tor. If you want to get more advanced, you can configure your Tor client on a firewall to bind to your internal IP but not your external IP.

Yes. Tor can be configured as a client or a relay on another machine, and allow other machines to be able to connect to it for anonymity. This is most useful in an environment where many computers want a gateway of anonymity to the rest of the world. However, be forewarned that with this configuration, anyone within your private network (existing between you and the Tor client/relay) can see what traffic you are sending in clear text. The anonymity doesn't start until you get to the Tor relay. Because of this, if you are the controller of your domain and you know everything's locked down, you will be OK, but this configuration may not be suitable for large private networks where security is key all around.

Configuration is simple, editing your torrc file's SocksListenAddress according to the following examples:

SocksListenAddress 127.0.0.1
SocksListenAddress 192.168.x.x:9100
SocksListenAddress 0.0.0.0:9100

You can state multiple listen addresses, in the case that you are part of several networks or subnets.

SocksListenAddress 192.168.x.x:9100 #eth0
SocksListenAddress 10.x.x.x:9100 #eth1

After this, your clients on their respective networks/subnets would specify a socks proxy with the address and port you specified SocksListenAddress to be. Please note that the SocksPort configuration option gives the port ONLY for localhost (127.0.0.1). When setting up your SocksListenAddress(es), you need to give the port with the address, as shown above. If you are interested in forcing all outgoing data through the central Tor client/relay, instead of the server only being an optional proxy, you may find the program iptables (for *nix) useful.

Configurem NoScript per permetre JavaScript de manera predeterminada al navegador Tor perquè molts llocs web no funcionen amb JavaScript desactivat. La majoria dels usuaris renunciarien completament a Tor si desactivem JavaScript de manera predeterminada perquè causaria molts problemes per a ells. En definitiva, volem que el navegador de Tor sigui el més segur possible, a més de fer-lo servir per a la majoria de les persones, de moment, això vol dir que JavaScript està habilitat per defecte.

For users who want to have JavaScript disabled on all HTTP sites by default, we recommend changing your Tor Browser's "Security Level" option. This can be done by navigating the Security icon (the small gray shield at the top-right of the screen), then clicking "Advanced Security Settings...". The "Standard" level allows JavaScript, but the "Safer" and "Safest" levels both block JavaScript on HTTP sites.

Consulteu les PMF de NoScript. Si creieu que aquest és un problema del navegador Tor, informeu-lo al nostre seguidor d'errors.

Tor mòbil

It will be, soon. In the meantime you can use F-Droid to download Tor Browser for Android by enabling the Guardian Project's Repository.

Learn how to add a repository to F-Droid.

While both Tor Browser for Android and Orbot are great, they serve different purposes. Tor Browser for Android is like the desktop Tor Browser, but on your mobile device. It is a one stop browser that uses the Tor network and tries to be as anonymous as possible. Orbot on the other hand is a proxy that will enable you to send the data from your other applications (E-Mail clients, instant messaging apps, etc.) through the Tor network; a version of Orbot is also inside of the Tor Browser for Android, and is what enables it to connect to the Tor network. That version, however, does not enable you to send other apps outside of the Tor Browser for Android through it. Depending on how you want to use the Tor network, either one or both of these could be a great option.

There is currently no supported method for running Tor Browser on older Windows Phones but in case of the newer Microsoft-branded/promoted phones, same steps as in Tor Browser for Android can be followed.

Recomanem una aplicació per a iOS anomenada Navegador Onion, que es de codi obert, utilitza l'enrutament Tor, i està desenvolupada per algú que treballa de prop amb el projecte Tor. No obstant això, Apple requereix que els navegadors d'iOS utilitzin alguna cosa anomenat Webkit, que impedeix que el navegador Onion tingui les mateixes proteccions de privadesa que el navegador Tor.

Learn more about Onion Browser. Download Onion Browser from the App Store.

The Guardian Project maintains Orbot (and other privacy applications) on Android. More info can be found on the Guardian Project's website.

Yes, there is a version of Tor Browser available specifically for Android. Installing Tor Browser for Android is all you need to run Tor on your Android device.

The Guardian Project provides the app Orbot which can be used to route other apps on your Android device over the Tor network, however only Tor Browser for Android is needed to browse the web with Tor.

Connexió al Tor

Proxy server errors can occur for a variety of reasons. You may try one or more of the following activities in case you encounter this error:

  • If you have an antivirus, it may be interfering with the Tor service. Disable the antivirus and restart the browser.
  • You should not have moved the Tor Browser folder from its original location to a different location. If you did this, revert the change.
  • You should also check the port that you are connecting with. Try a different port from the one currently in use, such as 9050 or 9150.
  • When all else fails, reinstall the browser. This time, make sure to install Tor Browser in a new directory, not over a previously installed browser.

If the error persists, please get in touch with us.

If you cannot reach the onion service you desire, make sure that you have entered the 16-character or, the newest format, 56-character onion address correctly; even a small mistake will stop Tor Browser from being able to reach the site. Si encara no podeu connectar-vos al servei de onion, torneu-ho a provar més tard. És possible que hi hagi un problema de connexió temporal o que els operadors del lloc hagin permès que es desconnectés sense previ avís.

You can also ensure that you're able to access other onion services by connecting to DuckDuckGo's onion service.

If you’re having trouble connecting, an error message may appear and you can select the option to "copy Tor log to clipboard". A continuació, enganxeu el registre de Tor en un fitxer de text o en un altre document.

If you don't see this option and you have Tor Browser open, you can navigate to the hamburger menu ("≡"), then click on "Preferences", and finally on "Tor" in the side bar. At the bottom of the page, next to the "View the Tor logs" text, click the button "View Logs...".

Alternatively, on GNU/Linux, to view the logs right in the terminal, navigate to the Tor Browser directory and launch the Tor Browser from the command line by running:

./start-tor-browser.desktop --verbose

or to save the logs to a file (default: tor-browser.log)

./start-tor-browser.desktop --log [file]

Heu de veure un d'aquests errors de registre comuns (busqueu les següents línies al vostre registre de Tor):

Common log error #1: Proxy connection failure

2017-10-29 09:23:40.800 [NOTICE] Opening Socks listener on 127.0.0.1:9150
2017-10-29 09:23:47.900 [NOTICE] Bootstrapped 5%: Connecting to directory server
2017-10-29 09:23:47.900 [NOTICE] Bootstrapped 10%: Finishing handshake with directory server
2017-10-29 09:24:08.900 [WARN] Proxy Client: unable to connect to xx..xxx..xxx.xx:xxxxx ("general SOCKS server failure")

Si veieu línies com aquestes al vostre registre de Tor, significa que no esteu connectant a un proxy SOCKS. Si es requereix un proxy SOCKS per a la configuració de la xarxa, assegureu-vos que heu introduït correctament els vostres detalls del proxy. Si no es requereix un proxy SOCKS, o no esteu segur, intenteu connectar-vos a la xarxa Tor sense un proxy SOCKS.

Common log error #2: Can’t reach guard relays

11/1/2017 21:11:43 PM.500 [NOTICE] Opening Socks listener on 127.0.0.1:9150
11/1/2017 21:11:44 PM.300 [NOTICE] Bootstrapped 80%: Connecting to the Tor network
11/1/2017 21:11:44 PM.300 [WARN] Failed to find node for hop 0 of our path. Discarding this circuit.
11/1/2017 21:11:44 PM.500 [NOTICE] Bootstrapped 85%: Finishing handshake with first hop
11/1/2017 21:11:45 PM.300 [WARN] Failed to find node for hop 0 of our path. Discarding this circuit.

Si veieu línies com aquestes en el vostre registre Tor, significa que Tor no s'ha pogut connectar al primer node del circuit Tor. Això podria significar que estàs en una xarxa censurada.

Intenteu connectar-vos amb ponts i això hauria de solucionar el problema.

Common log error #3: Failed to complete TLS handshake

13-11-17 19:52:24.300 [NOTICE] Bootstrapped 10%: Finishing handshake with directory server 
13-11-17 19:53:49.300 [WARN] Problem bootstrapping. Stuck at 10%: Finishing handshake with directory server. (DONE; DONE; count 10; recommendation warn; host [host] at xxx.xxx.xxx.xx:xxx) 
13-11-17 19:53:49.300 [WARN] 10 connections have failed: 
13-11-17 19:53:49.300 [WARN]  9 connections died in state handshaking (TLS) with SSL state SSLv2/v3 read server hello A in HANDSHAKE 
13-11-17 19:53:49.300 [WARN]  1 connections died in state connect()ing with SSL state (No SSL object)

Si veieu línies com aquesta al registre Tor, significa que Tor no ha pogut completar una encaixada de mans de TLS amb les autoritats del directori. Usar ponts probablement solucionarà això.

Common log error #4: Clock skew

19.11.2017 00:04:47.400 [NOTICE] Opening Socks listener on 127.0.0.1:9150 
19.11.2017 00:04:48.000 [NOTICE] Bootstrapped 5%: Connecting to directory server 
19.11.2017 00:04:48.200 [NOTICE] Bootstrapped 10%: Finishing handshake with directory server 
19.11.2017 00:04:48.800 [WARN] Received NETINFO cell with skewed time (OR:xxx.xx.x.xx:xxxx): It seems that our clock is behind by 1 days, 0 hours, 1 minutes, or that theirs is ahead. Tor requires an accurate clock to work: please check your time, timezone, and date settings.

Si veieu línies com aquesta en el vostre registre Tor, significa que el vostre rellotge del sistema no és correcte. Assegureu-vos que el rellotge s'estableixi amb precisió, inclosa la zona horària correcta. Torneu a iniciar Tor.

Un dels problemes més comuns que causa errors de connexió al navegador Tor és un rellotge del sistema incorrecte. Assegureu-vos que el rellotge del sistema i el fus horari estiguin configurats amb precisió. If this doesn't fix the problem, see the Troubleshooting page on the Tor Browser manual.

Censura

If you can't download Tor Browser through our website, you can get a copy of Tor Browser delivered to you via GetTor. GetTor és un servei que respon automàticament als missatges amb enllaços a la versió més recent del Navegador Tor , allotjada en una varietat de llocs menys susceptibles de ser censurats, com Dropbox, Google Drive i GitHub. You can also download Tor Browser from https://tor.eff.org or from https://tor.ccc.de. For more geographically specific links visit Tor: Mirrors

Envia un mail a gettor@torproject.org. In the body of the mail, write the name of your operating system (such as Windows, macOS, or Linux). GetTor will respond with an email containing links from which you can download Tor Browser, the cryptographic signature (needed for verifying the download), the fingerprint of the key used to make the signature, and the package’s checksum. Es pot oferir una selecció de programari de "32 bits" o "de 64 bits": això depèn del model de l'ordinador que utilitzeu; consulteu la documentació sobre l'ordinador per obtenir-ne més informació.

GetTor via Twitter is currently under maintenance. Please use the email instead.

El Navegador Tor pot, per descomptat, ajudar els usuaris a accedir al vostre lloc web des d'ubicacions on estigui blocat. Normalment, només cal baixar el Navegador Tor i utilitzar-lo per a navegar per la pàgina blocada per a poder accedir-hi. En llocs on hi ha una gran censura, tenim disponibles diverses opcions d’elusió de la censura, incloent-hi transports connectables.

Per a obtenir més informació, consulteu la secció de censura del manual d’usuari del Navegador Tor.

If you’re having trouble connecting, an error message may appear and you can select the option to "copy Tor log to clipboard". A continuació, enganxeu el registre de Tor en un fitxer de text o en un altre document.

If you don't see this option and you have Tor Browser open, you can navigate to the hamburger menu ("≡"), then click on "Preferences", and finally on "Tor" in the side bar. At the bottom of the page, next to the "View the Tor logs" text, click the button "View Logs...".

Alternatively, on GNU/Linux, to view the logs right in the terminal, navigate to the Tor Browser directory and launch the Tor Browser from the command line by running:

./start-tor-browser.desktop --verbose

or to save the logs to a file (default: tor-browser.log)

./start-tor-browser.desktop --log [file]

Heu de veure un d'aquests errors de registre comuns (busqueu les següents línies al vostre registre de Tor):

Common log error #1: Proxy connection failure

2017-10-29 09:23:40.800 [NOTICE] Opening Socks listener on 127.0.0.1:9150
2017-10-29 09:23:47.900 [NOTICE] Bootstrapped 5%: Connecting to directory server
2017-10-29 09:23:47.900 [NOTICE] Bootstrapped 10%: Finishing handshake with directory server
2017-10-29 09:24:08.900 [WARN] Proxy Client: unable to connect to xx..xxx..xxx.xx:xxxxx ("general SOCKS server failure")

Si veieu línies com aquestes al vostre registre de Tor, significa que no esteu connectant a un proxy SOCKS. Si es requereix un proxy SOCKS per a la configuració de la xarxa, assegureu-vos que heu introduït correctament els vostres detalls del proxy. Si no es requereix un proxy SOCKS, o no esteu segur, intenteu connectar-vos a la xarxa Tor sense un proxy SOCKS.

Common log error #2: Can’t reach guard relays

11/1/2017 21:11:43 PM.500 [NOTICE] Opening Socks listener on 127.0.0.1:9150
11/1/2017 21:11:44 PM.300 [NOTICE] Bootstrapped 80%: Connecting to the Tor network
11/1/2017 21:11:44 PM.300 [WARN] Failed to find node for hop 0 of our path. Discarding this circuit.
11/1/2017 21:11:44 PM.500 [NOTICE] Bootstrapped 85%: Finishing handshake with first hop
11/1/2017 21:11:45 PM.300 [WARN] Failed to find node for hop 0 of our path. Discarding this circuit.

Si veieu línies com aquestes en el vostre registre Tor, significa que Tor no s'ha pogut connectar al primer node del circuit Tor. Això podria significar que estàs en una xarxa censurada.

Intenteu connectar-vos amb ponts i això hauria de solucionar el problema.

Common log error #3: Failed to complete TLS handshake

13-11-17 19:52:24.300 [NOTICE] Bootstrapped 10%: Finishing handshake with directory server 
13-11-17 19:53:49.300 [WARN] Problem bootstrapping. Stuck at 10%: Finishing handshake with directory server. (DONE; DONE; count 10; recommendation warn; host [host] at xxx.xxx.xxx.xx:xxx) 
13-11-17 19:53:49.300 [WARN] 10 connections have failed: 
13-11-17 19:53:49.300 [WARN]  9 connections died in state handshaking (TLS) with SSL state SSLv2/v3 read server hello A in HANDSHAKE 
13-11-17 19:53:49.300 [WARN]  1 connections died in state connect()ing with SSL state (No SSL object)

Si veieu línies com aquesta al registre Tor, significa que Tor no ha pogut completar una encaixada de mans de TLS amb les autoritats del directori. Usar ponts probablement solucionarà això.

Common log error #4: Clock skew

19.11.2017 00:04:47.400 [NOTICE] Opening Socks listener on 127.0.0.1:9150 
19.11.2017 00:04:48.000 [NOTICE] Bootstrapped 5%: Connecting to directory server 
19.11.2017 00:04:48.200 [NOTICE] Bootstrapped 10%: Finishing handshake with directory server 
19.11.2017 00:04:48.800 [WARN] Received NETINFO cell with skewed time (OR:xxx.xx.x.xx:xxxx): It seems that our clock is behind by 1 days, 0 hours, 1 minutes, or that theirs is ahead. Tor requires an accurate clock to work: please check your time, timezone, and date settings.

Si veieu línies com aquesta en el vostre registre Tor, significa que el vostre rellotge del sistema no és correcte. Assegureu-vos que el rellotge s'estableixi amb precisió, inclosa la zona horària correcta. Torneu a iniciar Tor.

Els repetidors pont són repetidors Tor que no figuren en el directori Tor públic.

Això vol dir que els ISP o els governs que intenten blocar l'accés a la xarxa Tor no poden simplement blocar tots els ponts. Els ponts són útils per als usuaris de Tor sota règims opressors, i per a persones que volen una capa addicional de seguretat perquè estan preocupats que algú reconegui que estan connectats a una adreça IP Tor de repetidor públic.

Un pont és només un repetidor normal amb una configuració lleugerament diferent. See How do I run a bridge for instructions.

Diversos països, inclosos la Xina i l'Iran, han trobat maneres de detectar i blocar connexions als ponts de Tor. Obfsproxy bridges address this by adding another layer of obfuscation. La configuració d'un pont obfsproxy requereix un paquet de programari addicional i configuracions addicionals. See our page on pluggable transports for more info.

Snowflake is a pluggable transport available in Tor Browser to defeat internet censorship. Like a Tor bridge, a user can access the open internet when even regular Tor connections are censored. To use Snowflake is as easy as to switch to a new bridge configuration in Tor Browser.

This system is composed of three components: volunteers running Snowflake proxies, Tor users that want to connect to the internet, and a broker, that delivers snowflake proxies to users.

Volunteers willing to help users on censored networks can help by spinning short-lived proxies on their regular browsers. Check, how can I use Snowflake?

Snowflake uses the highly effective domain fronting technique to make a connection to one of the thousands of snowflake proxies run by volunteers. These proxies are lightweight, ephemeral, and easy to run, allowing us to scale Snowflake more easily than previous techniques.

For censored users, if your Snowflake proxy gets blocked, the broker will find a new proxy for you, automatically.

If you're interested in the technical details and specification, see the Snowflake Technical Overview and the project page.

Snowflake is available in Tor Browser stable for all platforms: Windows, macOS, GNU/Linux, and Android. You can also use Snowflake with Onion Browser on iOS.

If you're running Tor Browser for desktop for the first time, you can click on 'Tor Network Settings' on the start-up screen and then select 'Use a bridge'. Click on 'Select a built-in bridge' and choose 'snowflake' from the dropdown menu. Once you've selected Snowflake, scroll up and click 'Connect' to save your settings.

From within the browser, you can click on the hamburger menu ("≡"), then go to 'Preferences' and go to 'Tor'. Alternatively, you can also type about:preferences#tor in the url bar. Check 'Use a bridge' and 'Select a built-in bridge'. Then select 'snowflake' from the dropdown menu.

If your internet access is not censored, you should consider installing the Snowflake extension to help users in censored networks. When you run Snowflake on you regular browser, you will provide connection as a proxy to an entry node in the Tor Network, and that’s all.

Add-on

Firstly make sure you have WebRTC enabled. Then you can install this addon for Firefox or the add-on for Chrome which will let you become a Snowflake proxy. It can also inform you about how many people you have helped in the last 24 hours.

Web page

In a browser where WebRTC is enabled: If you don't want to add Snowflake to your browser, you can go to https://snowflake.torproject.org/embed and toggle the button to opt in to being a proxy. You shouldn't close that page if you want to remain a Snowflake proxy.

Users in China need to take a few steps to circumvent the Great Firewall and connect to the Tor network. First, get an updated version of Tor Browser: send an email to gettor@torproject.org with the subject "windows zh-cn" or other operating system (linux or macos)

After installing Tor Browser, you will probably not be able to connect directly to the Tor network, because the Great Firewall is blocking Tor. Therefore, the second step will be to obtain a bridge that works in China.

There are three options to unblock Tor in China:

  1. Snowflake: uses ephemeral proxies to connect to the Tor network. It's available in Tor Browser stable version (Desktop and Android). You can select Snowflake from Tor Browser's built-in bridge dropdown.
  2. Private and unlisted obfs4 bridges: users will need to request a private bridge to frontdesk@torproject.org with the phrase "private bridge" in the subject of the email or, if they are tech-savvy, they can run their own obfs4 bridge from outside China. It's important to note that bridges distributed by BridgeDB (HTTPS, email), and built-in obfs4 bridges bundled in Tor Browser most likely won't work.
  3. meek-azure: it looks like you are browsing a Microsoft website instead of using Tor. However, because it has a bandwidth limitation, this option will be quite slow. You can select meek-azure from Tor Browser's built-in bridges dropdown.

If one of these options below is not working, check your Tor logs and try another option.

You might be on a network that is blocking the Tor network, and so you should try using bridges. Some bridges are built in to Tor Browser and requires only a few steps to enable it. When you open Tor Browser for the first time, click "Tor Network Settings". Under the "Bridges" section, select the checkbox "Use a bridge", and choose the "Select a built-in bridge" option. From the dropdown, select whichever pluggable transport you'd like to use. Once you've selected the pluggable transport, scroll up and click "Connect" to save your settings.

Or, if you have Tor Browser running, click on "Preferences" (or "Options" on Windows) in the hamburger menu (≡) and then on "Tor" in the sidebar. In the "Bridges" section, select the checkbox "Use a bridge", and from the option "Select a built-in bridge", choose whichever pluggable transport you'd like to use from the dropdown. Your settings will automatically be saved once you close the tab.

If you need other bridges, you can get them at our Bridges website. For more information about bridges, see the Tor Browser manual.

De vegades, els llocs web bloquen els usuaris de Tor perquè no poden avaluar la diferència entre l'usuari Tor mitjà i el trànsit automatitzat. La millor manera que hem tingut per que els llocs desbloquin els usuaris de Tor és que els usuaris es posin en contacte directament amb els administradors del lloc. Alguna cosa així podria funcionar:

"Hola! He intentat accedir al vostre lloc xyz.com mentre feia servir el Navegador Tor i he descobert que no permet que els usuaris de Tor accedeixin al vostre lloc. Et convido a reconsiderar aquesta decisió; Tor és utilitzat per persones de tot el món per protegir la seva intimitat i lluitar contra la censura. Blocar els usuaris de Tor, probablement blocarà persones en països repressius que vulguin utilitzar una internet lliure, periodistes i investigadors que volen protegir-se de ser descoberts, denunciants, activistes i persones habituals que volen optar per un seguiment invasiu de tercers. Si us plau, prengui una posició forta a favor de la privadesa digital i la llibertat d'internet i permeti als usuaris de Tor accedir a xyz.com.Gràcies"

En el cas dels bancs i altres llocs web sensibles, també és habitual veure blocatge basat en la geografia (si un banc sap que en general accedeix als seus serveis d'un país i, de sobte, es connecta d'un repetidor de sortida a l'altre costat del món, el vostre compte pot estar blocat o suspès).

If you are unable to connect to an onion service, please see I cannot reach X.onion!.

HTTPS

The short answer is: Yes, you can browse normal HTTPS sites using Tor.

HTTPS Connections are used to secure communications over computer networks. You can read more about HTTPS here. Tor Browser has the HTTPS Everywhere plugin which automatically switches thousands of sites from unencrypted "HTTP" to more private "HTTPS".

Tor evita que els que espien sàpiguen quins llocs visiteu. Tanmateix, la informació enviada sense xifrar a Internet mitjançant HTTP simple encara pot ser interceptada pels operadors de repetidors de sortida o qualsevol persona que observi el trànsit entre el repetidor de sortida i el lloc web de destinació. Si el lloc que esteu visitant utilitza HTTPS, el trànsit que surt del relleu de sortida es xifrarà i no serà visible per als espies.

This visualization shows what information is visible to eavesdroppers with and without Tor Browser and HTTPS encryption.

La imatge següent mostra quina informació poden veure els tafaners amb el Navegador Tor i un xifratge HTTPS, i sense:

  • Feu clic al botó «Tor» per a saber quines dades poden veure els observadors quan utilitzeu el Tor. El botó es posarà de color verd per a indicar que el Tor està encès.
  • Feu clic al botó «HTTPS» per a saber quines dades poden veure els observadors quan utilitzeu HTTPS. El botó es posarà de color verd per a indicar que el Tor està encès.
  • Quan ambdós botons estan verds, es mostren les dades que poden veure els observadors quan utilitzeu ambdues eines.
  • Quan ambdós botons estan grisos, es mostren les dades que poden veure els observadors quan no utilitzeu cap de les dues eines.



DADES POTENCIALMENT VISIBLES
Lloc.com
El lloc web que s'està visitant.
usuari / contrasenya
Nom d'usuari i contrasenya utilitzats per a l'autenticació.
dades
Dades que s'estan transmetent.
ubicació
Ubicació en la xarxa de l'ordinador utilitzat per a visitar el lloc web (l'adreça IP pública).
Tor
Si s'està utilitzant el Tor o no.

Relay Operators

Tor guesses its IP address by asking the computer for its hostname, and then resolving that hostname. Often people have old entries in their /etc/hosts file that point to old IP addresses.

If that doesn't fix it, you should use the "Address" config option to specify the IP you want it to pick. If your computer is behind a NAT and it only has an internal IP address, see the following Support entry on dynamic IP addresses.

Also, if you have many addresses, you might also want to set "OutboundBindAddress" so external connections come from the IP you intend to present to the world.

If your relay is relatively new then give it time. Tor decides which relays it uses heuristically based on reports from Bandwidth Authorities. These authorities take measurements of your relay's capacity and, over time, directs more traffic there until it reaches an optimal load. The lifecycle of a new relay is explained in more depth in this blog post. If you've been running a relay for a while and still having issues then try asking on the tor-relays list.

Why Relay Load Varies

Tor manages bandwidth across the entire network. It does a reasonable job for most relays. But Tor's goals are different to protocols like BitTorrent. Tor wants low-latency web pages, which requires fast connections with headroom. BitTorrent wants bulk downloads, which requires using all the bandwidth.

We're working on a new bandwidth scanner, which is easier to understand and maintain. It will have diagnostics for relays that don't get measured, and relays that have low measurements.

Why does Tor need bandwidth scanners?

Most providers tell you the maximum speed of your local connection. But Tor has users all over the world, and our users connect to one or two Guard relays at random. So we need to know how well each relay can connect to the entire world.

So even if all relay operators set their advertised bandwidth to their local connection speed, we would still need bandwidth authorities to balance the load between different parts of the Internet.

What is a normal relay load?

It's normal for most relays to be loaded at 30%-80% of their capacity. This is good for clients: an overloaded relay has high latency. (We want enough relays to so that each relay is loaded at 10%. Then Tor would be almost as fast as the wider Internet).

Sometimes, a relay is slow because its processor is slow or its connections are limited. Other times, it is the network that is slow: the relay has bad peering to most other tor relays, or is a long distance away.

Finding Out what is Limiting a Relay

Lots of things can slow down a relay. Here's how to track them down.

System Limits

  • Check RAM, CPU, and socket/file descriptor usage on your relay

Tor logs some of these when it starts. Others can be viewed using top or similar tools.

Provider Limits

  • Check the Internet peering (bandwidth, latency) from your relay's provider to other relays. Relays transiting via Comcast have been slow at times. Relays outside North America and Western Europe are usually slower.

Tor Network Limits

Relay bandwidth can be limited by a relay's own observed bandwidth, or by the directory authorities' measured bandwidth. Here's how to find out which measurement is limiting your relay:

  • Check each of the votes for your relay on consensus-health (large page), and check the median. If your relay is not marked Running by some directory authorities:
    • Does it have the wrong IPv4 or IPv6 address?
    • Is its IPv4 or IPv6 address unreachable from some networks?
    • Are there more than 2 relays on its IPv4 address?

Otherwise, check your relay's observed bandwidth and bandwidth rate (limit). Look up your relay on Metrics. Then mouse over the bandwidth heading to see the observed bandwidth and relay bandwidth rate.

Here is some more detail and some examples: Drop in consensus weight and Rampup speed of Exit relay.

How to fix it

The smallest of these figures is limiting the bandwidth allocated to the relay.

  • If it's the bandwidth rate, increase the BandwidthRate/Burst or RelayBandwidthRate/Burst in your torrc.
  • If it's the observed bandwidth, your relay won't ask for more bandwidth until it sees itself getting faster. You need to work out why it is slow.
  • If it's the median measured bandwidth, your relay looks slow from a majority of bandwidth authorities. You need to work out why they measure it slow.

Doing Your Own Relay Measurements

If your relay thinks it is slow, or the bandwidth authorities think it is slow, you can test the bandwidth yourself:

  • Run a test using tor to see how fast tor can get on your network/CPU.
  • Run a test using tor and chutney to find out how fast tor can get on your CPU. Keep increasing the data volume until the bandwidth stops increasing.

If you allow exit connections, some services that people connect to from your relay will connect back to collect more information about you. For example, some IRC servers connect back to your identd port to record which user made the connection. (This doesn't really work for them, because Tor doesn't know this information, but they try anyway.) Also, users exiting from you might attract the attention of other users on the IRC server, website, etc. who want to know more about the host they're relaying through.

Another reason is that groups who scan for open proxies on the Internet have learned that sometimes Tor relays expose their socks port to the world. We recommend that you bind your socksport to local networks only.

In any case, you need to keep up to date with your security. See this article on security for Tor relays for more suggestions.

  • The exit relay is the most needed relay type but it also comes with the highest legal exposure and risk (and you should NOT run them from your home).
  • If you are looking to run a relay with minimal effort, fast guard relays are also very useful
  • Followed by bridges.

When an exit is misconfigured or malicious it's assigned the BadExit flag. This tells Tor to avoid exiting through that relay. In effect, relays with this flag become non-exits. If you got this flag then we either discovered a problem or suspicious activity when routing traffic through your exit and weren't able to contact you. Please reach out to the bad-relays team so we can sort out the issue.

When upgrading your Tor relay, or moving it on a different computer, the important part is to keep the same identity keys (stored in "keys/ed25519_master_id_secret_key" and "keys/secret_id_key" in your DataDirectory). Keeping backups of the identity keys so you can restore a relay in the future is the recommended way to ensure the reputation of the relay won't be wasted.

This means that if you're upgrading your Tor relay and you keep the same torrc and the same DataDirectory, then the upgrade should just work and your relay will keep using the same key. If you need to pick a new DataDirectory, be sure to copy your old keys/ed25519_master_id_secret_key and keys/secret_id_key over.

Note: As of Tor 0.2.7 we are using new generation identities for relays based on ed25519 elliptic curve cryptography. Eventually they will replace the old RSA identities, but that will happen in time, to ensure compatibility with older versions. Until then, each relay will have both an ed25519 identity (identity key file: keys/ed25519_master_id_secret_key) and a RSA identity (identity key file: keys/secret_id_key). You need to copy / backup both of them in order to restore your relay, change your DataDirectory or migrate the relay on a new computer.

We're looking for people with reasonably reliable Internet connections, that have at least 10 Mbit/s (Mbps) available bandwidth each way. If that's you, please consider running a Tor relay.

Even if you do not have at least 10 Mbit/s of available bandwidth you can still help the Tor network by running a Tor bridge with obfs4 support. In that case you should have at least 1 MBit/s of available bandwidth.

You can run a relay in Windows following this tutorials:

You should only run a Windows relay if you can run it 24/7. If you are unable to guarantee that, Snowflake is a better way to contribute your resources to the Tor network.

You're right, for the most part a byte into your Tor relay means a byte out, and vice versa. But there are a few exceptions:

If you open your DirPort, then Tor clients will ask you for a copy of the directory. The request they make (an HTTP GET) is quite small, and the response is sometimes quite large. This probably accounts for most of the difference between your "write" byte count and your "read" byte count.

Another minor exception shows up when you operate as an exit node, and you read a few bytes from an exit connection (for example, an instant messaging or ssh connection) and wrap it up into an entire 512 byte cell for transport through the Tor network.

If your Tor relay is using more memory than you'd like, here are some tips for reducing its footprint:

  • If you're on Linux, you may be encountering memory fragmentation bugs in glibc's malloc implementation. That is, when Tor releases memory back to the system, the pieces of memory are fragmented so they're hard to reuse. The Tor tarball ships with OpenBSD's malloc implementation, which doesn't have as many fragmentation bugs (but the tradeoff is higher CPU load). You can tell Tor to use this malloc implementation instead: ./configure --enable-openbsd-malloc.
  • If you're running a fast relay, meaning you have many TLS connections open, you are probably losing a lot of memory to OpenSSL's internal buffers (38KB+ per socket). We've patched OpenSSL to release unused buffer memory more aggressively. If you update to OpenSSL 1.0.0 or newer, Tor's build process will automatically recognize and use this feature.
  • If you still can't handle the memory load, consider reducing the amount of bandwidth your relay advertises. Advertising less bandwidth means you will attract fewer users, so your relay shouldn't grow as large. See the MaxAdvertisedBandwidth option in the man page.

All of this said, fast Tor relays do use a lot of ram. It is not unusual for a fast exit relay to use 500-1000 MB of memory.

We aim to make setting up a Tor relay easy and convenient:

  • It's fine if the relay goes offline sometimes. The directories notice this quickly and stop advertising the relay. Just try to make sure it's not too often, since connections using the relay when it disconnects will break.
  • Each Tor relay has an exit policy that specifies what sort of outbound connections are allowed or refused from that relay. If you are uncomfortable allowing people to exit from your relay, you can set it up to only allow connections to other Tor relays.
  • Your relay will passively estimate and advertise its recent bandwidth capacity, so high-bandwidth relays will attract more users than low-bandwidth ones. Therefore, having low-bandwidth relays is useful too.

On relay search we show an amber dot next to the relay nickname when this is overloaded. This means that one or many of the following load metrics have been triggered:

  • Any Tor OOM invocation due to memory pressure
  • Any ntor onionskins are dropped
  • TCP port exhaustion
  • DNS timeout reached

Note that if a relay reaches an overloaded state we show it for 72 hours after the relay has recovered.

If you notice that your relay is overloaded please:

1. Check https://status.torproject.org/ for any known issues in the "Tor network" category.

2. Consider tuning sysctl for your system for network, memory and CPU load.

If you are experiencing TCP port exhaustion consider expanding your local port range

‪sysctl -w net.ipv4.ip_local_port_range="15000 64000"

o

echo 15000 64000 > /proc/sys/net/ipv4/ip_local_port_range

If you are experiencing DNS timeout, you should investigate if this is a network or a resolver issue.

In Linux in resolve.conf there is an option to set a timeout:

timeout:n
  Sets  the  amount of time the resolver will wait for a response from a remote
  name server before retrying the query via a different name server.
  This may not be the total time taken by any resolver API call and there is no guarantee
  that a single resolver API call maps to a single timeout.
  Measured in seconds, the default is RES_TIMEOUT (currently 5, see <resolv.h>).
  The value for this option is silently capped to 30.

Check $ man resolve.conf for more information.

3. Consider enabling MetricsPort to understand what is happening.

MetricsPort data for relays has been introduced since version >= 0.4.7.1-alpha, while the overload data has been added to the relay descriptors since 0.4.6+.

It's important to understand that exposing tor metrics publicly is dangerous to the Tor network users. Please take extra precaution and care when opening this port. Set a very strict access policy with MetricsPortPolicy and consider using your operating systems firewall features for defense in depth.

Here is an example of what output enabling MetricsPort will produce:

‪# HELP tor_relay_load_onionskins_total Total number of onionskins handled
‪# TYPE tor_relay_load_onionskins_total counter
tor_relay_load_onionskins_total{type="tap",action="processed"} 0
tor_relay_load_onionskins_total{type="tap",action="dropped"} 0
tor_relay_load_onionskins_total{type="fast",action="processed"} 0
tor_relay_load_onionskins_total{type="fast",action="dropped"} 0
tor_relay_load_onionskins_total{type="ntor",action="processed"} 0
tor_relay_load_onionskins_total{type="ntor",action="dropped"} 0
‪# HELP tor_relay_exit_dns_query_total Total number of DNS queries done by this relay
‪# TYPE tor_relay_exit_dns_query_total counter
tor_relay_exit_dns_query_total{record="A"} 0
tor_relay_exit_dns_query_total{record="PTR"} 0
tor_relay_exit_dns_query_total{record="AAAA"} 0
‪# HELP tor_relay_exit_dns_error_total Total number of DNS errors encountered by this relay
‪# TYPE tor_relay_exit_dns_error_total counter
tor_relay_exit_dns_error_total{record="A",reason="success"} 0
tor_relay_exit_dns_error_total{record="A",reason="format"} 0
tor_relay_exit_dns_error_total{record="A",reason="serverfailed"} 0
tor_relay_exit_dns_error_total{record="A",reason="notexist"} 0
tor_relay_exit_dns_error_total{record="A",reason="notimpl"} 0
tor_relay_exit_dns_error_total{record="A",reason="refused"} 0
tor_relay_exit_dns_error_total{record="A",reason="truncated"} 0
tor_relay_exit_dns_error_total{record="A",reason="unknown"} 0
tor_relay_exit_dns_error_total{record="A",reason="timeout"} 0
tor_relay_exit_dns_error_total{record="A",reason="shutdown"} 0
tor_relay_exit_dns_error_total{record="A",reason="cancel"} 0
tor_relay_exit_dns_error_total{record="A",reason="nodata"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="success"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="format"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="serverfailed"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="notexist"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="notimpl"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="refused"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="truncated"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="unknown"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="timeout"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="shutdown"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="cancel"} 0
tor_relay_exit_dns_error_total{record="PTR",reason="nodata"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="success"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="format"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="serverfailed"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="notexist"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="notimpl"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="refused"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="truncated"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="unknown"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="timeout"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="shutdown"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="cancel"} 0
tor_relay_exit_dns_error_total{record="AAAA",reason="nodata"} 0
‪# HELP tor_relay_load_tcp_exhaustion_total Total number of times we ran out of TCP ports
‪# TYPE tor_relay_load_tcp_exhaustion_total counter
tor_relay_load_tcp_exhaustion_total 0
‪# HELP tor_relay_load_socket_total Total number of sockets
‪# TYPE tor_relay_load_socket_total gauge
tor_relay_load_socket_total{state="opened"} 135
tor_relay_load_socket_total 1048544
‪# HELP tor_relay_load_oom_bytes_total Total number of bytes the OOM has freed by subsystem
‪# TYPE tor_relay_load_oom_bytes_total counter
tor_relay_load_oom_bytes_total{subsys="cell"} 0
tor_relay_load_oom_bytes_total{subsys="dns"} 0
tor_relay_load_oom_bytes_total{subsys="geoip"} 0
tor_relay_load_oom_bytes_total{subsys="hsdir"} 0
‪# HELP tor_relay_load_global_rate_limit_reached_total Total number of global connection bucket limit reached
‪# TYPE tor_relay_load_global_rate_limit_reached_total counter
tor_relay_load_global_rate_limit_reached_total{side="read"} 0
tor_relay_load_global_rate_limit_reached_total{side="write"} 0

Let's find out what some of these lines actually mean:

tor_relay_load_onionskins_total{type="ntor",action="dropped"} 0

When a relay starts seeing "dropped", it is a CPU/RAM problem usually.

Tor is sadly single threaded except for when the "onion skins" are processed. The "onion skins" are the cryptographic work that needs to be done on the famous "onion layers" in every circuits.

When tor processes the layers we use a thread pool and outsource all of that work to that pool. It can happen that this pool starts dropping work due to memory or CPU pressure and this will trigger an overload state.

If your server is running at capacity this will likely be triggered.

tor_relay_exit_dns_error_total{...}

Any counter in the "*_dns_error_total" realm indicates a DNS problem.

DNS timeouts issues only apply to Exit nodes. If tor starts noticing DNS timeouts, you'll get the overload flag. This might not be because your relay is overloaded in terms of resources but it signals a problem on the network.

DNS timeouts at the Exits are a huge UX problem for tor users. Therefore Exit operators really need to address these issues to help the network.

tor_relay_load_oom_bytes_total{...}

An Out-Of-Memory invocation indicates a RAM problem. The relay might need more RAM or it is leaking memory. If you noticed that the tor process is leaking memory, please report the issue via either GitLab or send an email to the tor-relays mailing list.

Tor has its own OOM handler and it is invoked when 75%, of the total memory tor thinks is available, is reached. Thus, let say tor thinks it can use 2GB in total then at 1.5GB of memory usage, it will start freeing memory. That is considered an overload state.

To estimate the amount of memory it has available, when tor starts, it will use MaxMemInQueues or, if not set, will look at the total RAM available on the system and apply this algorithm:

    if RAM >= 8GB {
      memory = RAM * 40%
    } else {
      memory = RAM * 75%
    }
    /* Capped. */
    memory = min(memory, 8GB) -> [8GB on 64bit and 2GB on 32bit)
    /* Minimum value. */
    memory = max(250MB, memory)

To avoid an overloaded state we recommend to run a relay above 2GB of RAM on 64bit. 4GB is advised, although of course it doesn't hurt to add more RAM if you can.

One might notice that tor could be called by the OS OOM handler itself. Because tor takes the total memory on the system when it starts, if the overall system has many other applications running using RAM, it ends up eating too much memory. In this case the OS could OOM tor, without tor even noticing memory pressure.

tor_relay_load_socket_total


tor_relay_load_tcp_exhaustion_total

These lines indicate the relay is running out of sockets or TCP ports. If the issue is socket related the solution is to increase ulimit -n for the tor process

If the solution is related to TCP ports exhaustion try to tune sysctl as described above.

tor_relay_load_global_rate_limit_reached_total

If this counter is incremented by some noticeable value over a short period of time then it indicates the relay is congested. It is likely being used as a Guard by a big onion service or for an ongoing DDoS on the network.

If your relay is still overloaded and you don't know why, please get in touch with network-report@torproject.org. You can encrypt your email using network-report OpenPGP key.

If you're using Debian or Ubuntu especially, there are a number of benefits to installing Tor from the Tor Project's repository.

  • Your ulimit -n gets set to 32768 high enough for Tor to keep open all the connections it needs.
  • A user profile is created just for Tor, so Tor doesn't need to run as root.
  • An init script is included so that Tor runs at boot.
  • Tor runs with --verify-config, so that most problems with your config file get caught.
  • Tor can bind to low level ports, then drop privileges.

All outgoing connections must be allowed, so that each relay can communicate with every other relay.

In many jurisdictions, Tor relay operators are legally protected by the same common carrier regulations that prevent internet service providers from being held liable for third-party content that passes through their network. Exit relays that filter some traffic would likely forfeit those protections.

Tor promotes free network access without interference. Exit relays must not filter the traffic that passes through them to the internet. Exit relays found to be filtering traffic will get the BadExit flag once detected.

No. Si l'aplicació de la llei s'interessa pel trànsit des del teu repetidor de sortida, és possible que els agents s'apoderin de la vostra computadora. Per aquest motiu, és millor no executar el repetidor de sortida a casa o utilitzant la vostra connexió a Internet desde casa.

al contrari, considereu executar el repetidor de sortida en una instal·lació comercial que sigui compatible amb Tor. Tingueu una adreça IP independent per al vostre repetidor de sortida i no enruteu el vostre propi trànsit a través d'ell. Per descomptat, haureu d'evitar mantenir qualsevol informació personal o sensible a l'ordinador que allotgeu el vostre repetidor de sortida.

  • No utilitzeu els paquets en els dipòsits d'Ubuntu. No s'actualitzen de forma fiable. Si els utilitzes, pots perdre estabilitat important i correccions de seguretat.
  • Determineu la vostra versió d'Ubuntu executant el següent comandament:
     ‪$ lsb_release -c
    
  • As root, add the following lines to /etc/apt/sources.list. Replace 'version' with the version you found in the previous step:
     deb https://deb.torproject.org/torproject.org version main
     deb-src https://deb.torproject.org/torproject.org version main
    
  • Afegiu la clau gpg usada per signar els paquets executant les ordres següents:
     ‪$ curl https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | sudo apt-key add -
    
  • Executeu les ordres següents per instal·lar tor i comproveu les seves signatures:
     ‪$ sudo apt-get update
     ‪$ sudo apt-get install tor deb.torproject.org-keyring
    

In simple words, it works like this:

  • There is a primary ed25519 identity secret key file named "ed25519_master_id_secret_key". This is the most important one, so make sure you keep a backup in a secure place - the file is sensitive and should be protected. Tor could encrypt it for you if you generate it manually and enter a password when asked.
  • A medium term signing key named "ed25519_signing_secret_key" is generated for Tor to use. Also, a certificate is generated named "ed25519_signing_cert" which is signed by the primary identity secret key and confirms that the medium term signing key is valid for a certain period of time. The default validity is 30 days, but this can be customized by setting "SigningKeyLifetime N days|weeks|months" in torrc.
  • There is also a primary public key named "ed25519_master_id_public_key", which is the actual identity of the relay advertised in the network. This one is not sensitive and can be easily computed from "ed5519_master_id_secret_key".

Tor will only need access to the medium term signing key and certificate as long as they are valid, so the primary identity secret key can be kept outside DataDirectory/keys, on a storage media or a different computer. You'll have to manually renew the medium term signing key and certificate before they expire otherwise the Tor process on the relay will exit upon expiration.

This feature is optional, you don't need to use it unless you want to. If you want your relay to run unattended for longer time without having to manually do the medium term signing key renewal on regular basis, best to leave the primary identity secret key in DataDirectory/keys, just make a backup in case you'll need to reinstall it. If you want to use this feature, you can consult our more detailed guide on the topic.

Since it's now a guard, clients are using it less in other positions, but not many clients have rotated their existing guards out to use it as a guard yet. Read more details in this blog post or in Changing of the Guards: A Framework for Understanding and Improving Entry Guard Selection in Tor.

Great. If you want to run several relays to donate more to the network, we're happy with that. But please don't run more than a few dozen on the same network, since part of the goal of the Tor network is dispersal and diversity.

If you do decide to run more than one relay, please set the "MyFamily" config option in the torrc of each relay, listing all the relays (comma-separated) that are under your control:

MyFamily $fingerprint1,$fingerprint2,$fingerprint3

where each fingerprint is the 40 character identity fingerprint (without spaces).

That way, Tor clients will know to avoid using more than one of your relays in a single circuit. You should set MyFamily if you have administrative control of the computers or of their network, even if they're not all in the same geographic location.

The accounting options in the torrc file allow you to specify the maximum amount of bytes your relay uses for a time period.

    AccountingStart day week month [day] HH:MM

This specifies when the accounting should reset. For instance, to setup a total amount of bytes served for a week (that resets every Wednesday at 10:00am), you would use:

    AccountingStart week 3 10:00
    AccountingMax 500 GBytes

This specifies the maximum amount of data your relay will send during an accounting period, and the maximum amount of data your relay will receive during an account period. When the accounting period resets (from AccountingStart), then the counters for AccountingMax are reset to 0.

Example: Let's say you want to allow 50 GB of traffic every day in each direction and the accounting should reset at noon each day:

    AccountingStart day 12:00
    AccountingMax 50 GBytes

Note that your relay won't wake up exactly at the beginning of each accounting period. It will keep track of how quickly it used its quota in the last period, and choose a random point in the new interval to wake up. This way we avoid having hundreds of relays working at the beginning of each month but none still up by the end.

If you have only a small amount of bandwidth to donate compared to your connection speed, we recommend you use daily accounting, so you don't end up using your entire monthly quota in the first day. Just divide your monthly amount by 30. You might also consider rate limiting to spread your usefulness over more of the day: if you want to offer X GB in each direction, you could set your RelayBandwidthRate to 20*X KBytes. For example, if you have 50 GB to offer each way, you might set your RelayBandwidthRate to 1000 KBytes: this way your relay will always be useful for at least half of each day.

    AccountingStart day 0:00
    AccountingMax 50 GBytes
    RelayBandwidthRate 1000 KBytes
    RelayBandwidthBurst 5000 KBytes # allow higher bursts but maintain average

Tor has partial support for IPv6 and we encourage every relay operator to enable IPv6 functionality in their torrc configuration files when IPv6 connectivity is available. For the time being Tor will require IPv4 addresses on relays, you can not run a Tor relay on a host with IPv6 addresses only.

The parameters assigned in the AccountingMax and BandwidthRate apply to both client and relay functions of the Tor process. Thus you may find that you are unable to browse as soon as your Tor goes into hibernation, signaled by this entry in the log:

Bandwidth soft limit reached; commencing hibernation.
No new connections will be accepted

The solution is to run two Tor processes - one relay and one client, each with its own config. One way to do this (if you are starting from a working relay setup) is as follows:

  • In the relay Tor torrc file, simply set the SocksPort to 0.
  • Create a new client torrc file from the torrc.sample and ensure it uses a different log file from the relay. One naming convention may be torrc.client and torrc.relay.
  • Modify the Tor client and relay startup scripts to include -f /path/to/correct/torrc.
  • In Linux/BSD/Mac OS X, changing the startup scripts to Tor.client and Tor.relay may make separation of configs easier.

Great. That's exactly why we implemented exit policies.

Each Tor relay has an exit policy that specifies what sort of outbound connections are allowed or refused from that relay. The exit policies are propagated to Tor clients via the directory, so clients will automatically avoid picking exit relays that would refuse to exit to their intended destination. This way each relay can decide the services, hosts, and networks it wants to allow connections to, based on abuse potential and its own situation. Read the Support entry on issues you might encounter if you use the default exit policy, and then read Mike Perry's tips for running an exit node with minimal harassment.

The default exit policy allows access to many popular services (e.g. web browsing), but restricts some due to abuse potential (e.g. mail) and some since the Tor network can't handle the load (e.g. default file-sharing ports). You can change your exit policy by editing your torrc file. If you want to avoid most if not all abuse potential, set it to "reject *:*". This setting means that your relay will be used for relaying traffic inside the Tor network, but not for connections to external websites or other services.

If you do allow any exit connections, make sure name resolution works (that is, your computer can resolve Internet addresses correctly). If there are any resources that your computer can't reach (for example, you are behind a restrictive firewall or content filter), please explicitly reject them in your exit policy otherwise Tor users will be impacted too.

Tor can handle relays with dynamic IP addresses just fine. Just leave the "Address" line in your torrc blank, and Tor will guess.

The default open ports are listed below but keep in mind that, any port or ports can be opened by the relay operator by configuring it in torrc or modifying the source code. The default according to src/or/policies.c (line 85 and line 1901) from the source code release release-0.4.6:

reject 0.0.0.0/8
reject 169.254.0.0/16
reject 127.0.0.0/8
reject 192.168.0.0/16
reject 10.0.0.0/8
reject 172.16.0.0/12

reject *:25
reject *:119
reject *:135-139
reject *:445
reject *:563
reject *:1214
reject *:4661-4666
reject *:6346-6429
reject *:6699
reject *:6881-6999
accept *:*

BridgeDB implements four mechanisms to distribute bridges: HTTPS, Moat, Email, and Reserved. Bridge operators can check which mechanism their bridge is using, on the Relay Search. Enter the bridge's <HASHED FINGERPRINT> in the form and click "Search".

Operators can also choose which distribution method their bridge uses. To change the method, modify the BridgeDistribution setting in the torrc file to one of these: https, moat, email, none, any.

Read more on the Bridges post-install guide.

Yes, you do get better anonymity against some attacks.

The simplest example is an attacker who owns a small number of Tor relays. They will see a connection from you, but they won't be able to know whether the connection originated at your computer or was relayed from somebody else.

There are some cases where it doesn't seem to help: if an attacker can watch all of your incoming and outgoing traffic, then it's easy for them to learn which connections were relayed and which started at you. (In this case they still don't know your destinations unless they are watching them too, but you're no better off than if you were an ordinary client.)

There are also some downsides to running a Tor relay. First, while we only have a few hundred relays, the fact that you're running one might signal to an attacker that you place a high value on your anonymity. Second, there are some more esoteric attacks that are not as well-understood or well-tested that involve making use of the knowledge that you're running a relay -- for example, an attacker may be able to "observe" whether you're sending traffic even if they can't actually watch your network, by relaying traffic through your Tor relay and noticing changes in traffic timing.

It is an open research question whether the benefits outweigh the risks. A lot of that depends on the attacks you are most worried about. For most users, we think it's a smart move.

See portforward.com for directions on how to port forward with your NAT/router device.

If your relay is running on a internal net, you need to setup port forwarding. Forwarding TCP connections is system dependent but the firewalled-clients FAQ entry offers some examples on how to do this.

Also, here's an example of how you would do this on GNU/Linux if you're using iptables:

/sbin/iptables -A INPUT -i eth0 -p tcp --destination-port 9001 -j ACCEPT

You may have to change "eth0" if you have a different external interface (the one connected to the Internet). Chances are you have only one (except the loopback) so it shouldn't be too hard to figure out.

There are two options you can add to your torrc file:

BandwidthRate is the maximum long-term bandwidth allowed (bytes per second). For example, you might want to choose "BandwidthRate 10 MBytes" for 10 megabytes per second (a fast connection), or "BandwidthRate 500 KBytes" for 500 kilobytes per second (a decent cable connection). The minimum BandwidthRate setting is 75 kilobytes per second.

BandwidthBurst is a pool of bytes used to fulfill requests during short periods of traffic above BandwidthRate but still keeps the average over a long period to BandwidthRate. A low Rate but a high Burst enforces a long-term average while still allowing more traffic during peak times if the average hasn't been reached lately. For example, if you choose "BandwidthBurst 500 KBytes" and also use that for your BandwidthRate, then you will never use more than 500 kilobytes per second; but if you choose a higher BandwidthBurst (like 5 MBytes), it will allow more bytes through until the pool is empty.

If you have an asymmetric connection (upload less than download) such as a cable modem, you should set BandwidthRate to less than your smaller bandwidth (Usually that's the upload bandwidth). Otherwise, you could drop many packets during periods of maximum bandwidth usage - you may need to experiment with which values make your connection comfortable. Then set BandwidthBurst to the same as BandwidthRate.

Linux-based Tor nodes have another option at their disposal: they can prioritize Tor traffic below other traffic on their machine, so that their own personal traffic is not impacted by Tor load. A script to do this can be found in the Tor source distribution's contrib directory.

Additionally, there are hibernation options where you can tell Tor to only serve a certain amount of bandwidth per time period (such as 100 GB per month). These are covered in the hibernation entry below.

Note that BandwidthRate and BandwidthBurst are in Bytes, not Bits.

Serveis Onion

How do I know if I'm using v2 or v3 onion services?

You can identify v3 onion addresses by their 56 character length, e.g. Tor Project's v2 address:http://expyuzz4wqqyqhjn.onion/, and Tor Project's v3 address: http://2gzyxa5ihm7nsggfxnu52rck2vv4rvmdlkiu3zzui5du4xyclen53wid.onion/

If you're an onion service administrator, you must upgrade to v3 onion services as soon as possible. If you're a user, please ensure that you update your bookmarks to the website's v3 onion addresses.

What is the timeline for the v2 deprecation?

In September 2020, Tor started warning onion service operators and clients that v2 will be deprecated and obsolete in version 0.4.6. Tor Browser started warning users in June, 2021.

In July 2021, 0.4.6 Tor will no longer support v2 and support will be removed from the code base.

In October 2021, we will release new Tor client stable versions for all supported series that will disable v2.

You can read more in the Tor Project's blog post Onion Service version 2 deprecation timeline.

Can I keep using my v2 onion address? Can I access my v2 onion after September? Is this a backward-incompatible change?

V2 onion addresses are fundamentally insecure. If you have a v2 onion, we recommend you migrate now. This is a backward incompatible change: v2 onion services will not be reachable after September 2021.

What is the recommendation for developers to migrate? Any tips on how to spread the new v3 addresses to people?

In torrc, to create a version 3 address, you simply need to create a new service just as you did your v2 service, with these two lines:

HiddenServiceDir /full/path/to/your/new/v3/directory/
HiddenServicePort <virtual port> <target-address>:<target-port>

The default version is now set to 3 so you don't need to explicitly set it. Restart tor, and look on your directory for the new address. If you wish to keep running your version 2 service until it is deprecated to provide a transition path to your users, add this line to the configuration block of your version 2 service:

HiddenServiceVersion 2

This will allow you to identify in your configuration file which one is which version.

If you have Onion-Location configured on your website, you need to set the header with your new v3 address. For technical documentation about running onion services, please read the Onion Services page in our Community portal.

I didn't see the announcement, can I get more time to migrate?

No, v2 onion connections will start failing nowish, first slowly, then suddenly. It's time to move away.

Will services start failing to be reached in September, or before already?

Already, introduction points are not in Tor 0.4.6 anymore, so they will not be reachable if relay operators update.

As a website administrator, can I redirect users from my v2 onion to v3?

Yes, it will work until the v2 onion address is unreachable. You may want to encourage users to update their bookmarks.

Are v3 onion services going to help in mitigating DDoS problems?

Yes, we are continuously working on improving onion services security. Some of the work we have in our roadmap is ESTABLISH_INTRO Cell DoS Defense Extension, Res tokens: Anonymous Credentials for Onion Service DoS Resilience, and A First Take at PoW Over Introduction Circuits. For an overview about these proposals, read the detailed blog post How to stop the onion denial (of service).

When browsing an Onion Service, Tor Browser displays different onion icons in the address bar indicating the security of the current webpage.

Image of an onion An onion means:

  • The Onion Service is served over HTTP, or HTTPS with a CA-Issued certificate.
  • The Onion Service is served over HTTPS with a Self-Signed certificate.

Image of an onion with a red slash An onion with a red slash means:

  • The Onion Service is served with a script from an insecure URL.

Image of an onion with a caution sign An onion with caution sign means:

  • The Onion Service is served over HTTPS with an expired Certificate.
  • The Onion Service is served over HTTPS with a wrong Domain.
  • The Onion Service is served with a mixed form over an insecure URL.

If you cannot reach the onion service you desire, make sure that you have entered the 16-character or, the newest format, 56-character onion address correctly; even a small mistake will stop Tor Browser from being able to reach the site. Si encara no podeu connectar-vos al servei de onion, torneu-ho a provar més tard. És possible que hi hagi un problema de connexió temporal o que els operadors del lloc hagin permès que es desconnectés sense previ avís.

You can also ensure that you're able to access other onion services by connecting to DuckDuckGo's onion service.

Els serveis de onion permeten que la gent navegui, però també publiqui de manera anònima, inclosa la publicació de llocs web anònims.

Els serveis de onion també es basen en el xat i l'intercanvi d'arxius sense metadades, una interacció més segura entre els periodistes i les seves fonts, com ara SecureDrop o OnionShare, actualitzacions de programari més segures i formes més segures d'arribar a llocs web populars com Facebook.

These services use the special-use top level domain (TLD) .onion (instead of .com, .net, .org, etc.) and are only accessible through the Tor network.

When accessing a website that uses an onion service, Tor Browser will show at the URL bar an icon of an onion displaying the state of your connection: secure and using an onion service.

Onion icon

Els llocs web que només són accessibles per Tor són els anomenats "onions" i finalitzen en el TLD .onion. For example, the DuckDuckGo onion is https://duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion/. Podeu accedir a aquests llocs web utilitzant el navegador Tor. Les adreces han de ser compartides amb vostè per l'amfitrió del lloc web, ja que les onions no estan indexades en els motors de cerca de la manera típica que tenen els llocs web de vanilla.

Onion-Location is a new HTTP header that web sites can use to advertise their onion counterpart. If the web site that you're visiting has an onion site available, a purple suggestion pill will prompt at the URL bar saying ".onion available". When you click on ".onion available", the web site will be reloaded and redirected to its onion counterpart. At the moment, Onion-Location is available for Tor Browser desktop (Windows, macOS and GNU/Linux). You can learn more about Onion-Location in the Tor Browser Manual. If you're an onion service operator, learn how to configure Onion-Location in your onion site.

An authenticated onion service is an onion service that requires you to provide an authentication token (in this case, a private key) before accessing the service. The private key is not transmitted to the service, and it's only used to decrypt its descriptor locally. You can get the access credentials from the onion service operator. Reach out to the operator and request access. Learn more about how to use onion authentication in Tor Browser. If you want to create an onion service with client authentication, please see the Client Authorization in the Community portal.

Miscel·lània

No. After eleven beta releases, we discontinued support of Tor Messenger. Encara creiem en la capacitat de Tor d'utilitzar-se en una aplicació de missatgeria, però no tenim els recursos per fer-ho en aquest moment. Do you? Contact us.

Vidalia ja no es manté o és suportat. Una gran part de les funcions que Vidalia ofereix ara s'ha integrat al propi navegador Tor.

No, no oferim cap servei en línia. Podeu trobar una llista de tots els nostres projectes de programari a la nostra pàgina de projectes.

Tor no guarda registres que puguin identificar un usuari concret. Realitzem mesures segures sobre com funciona la xarxa, que podeu consultar a Tor Metrics.

Ho sentim molt, però ha estat infectat amb programari maliciós. El projecte Tor no ha creat aquest programari maliciós. Els autors del programari maliciós us demanen que baixeu el navegador Tor probablement per contactar-los de forma anònima amb el rescat que us demanen.

Si aquesta és la primera introducció al navegador Tor, entenem que podríeu pensar que som persones dolentes que habilitem persones encara pitjors.

Però consideri que el nostre programari s'utilitza diàriament per a diversos propòsits per activistes de drets humans, periodistes, supervivents de violència domèstica, denunciants, agents de policia i molts altres. Malauradament, la protecció que el nostre programari pot proporcionar a aquests grups de persones també pot ser maltractat pels criminals i els autors de malware. El projecte Tor no dona suport ni excusa l'ús del nostre programari per a fins maliciosos.

No recomanem utilitzar Tor amb BitTorrent. Per obtenir més informació, consulteu la nostra publicació de bloc sobre el tema.

Tor està finançat per diversos patrocinadors, incloent agències federals nord-americanes, fundacions privades i donants individuals. Check out a list of all our sponsors and a series of blog posts on our financial reports.

We feel that talking openly about our sponsors and funding model is the best way to maintain trust with our community. Sempre busquem més diversitat en les nostres fonts de finançament, especialment de fundacions i particulars.

Tor està dissenyat per defensar els drets humans i la privadesa evitant que ningú censuri coses, fins i tot nosaltres. Odiem que hi ha algunes persones que utilitzen Tor per fer coses terribles, però no podem fer res per desfer-se'n sense que també perjudiquem als activistes de drets humans, periodistes, superviventgs d'abusos i altres persones que utilitzen Tor per a coses bones. Si volguéssim blocar determinades persones d'utilitzar Tor, bàsicament hauríem afegit una porta del darrere al programari, que obriria als nostres usuaris vulnerabilitats, atacs de mals règims i altres adversaris.

Gràcies pel teu suport! Podeu trobar més informació sobre la donació a les nostres preguntes freqüents sobre els donants.

For sharing files over Tor, OnionShare is a good option. OnionShare is an open source tool for securely and anonymously sending and receiving files using Tor onion services. It works by starting a web server directly on your computer and making it accessible as an unguessable Tor web address that others can load in Tor Browser to download files from you, or upload files to you. It doesn't require setting up a separate server, using a third party file-sharing service, or even logging into an account.

Unlike services like email, Google Drive, DropBox, WeTransfer, or nearly any other way people typically send files to each other, when you use OnionShare you don't give any companies access to the files that you're sharing. So long as you share the unguessable web address in a secure way (like pasting it in an encrypted messaging app), no one but you and the person you're sharing with can access the files.

OnionShare is developed by Micah Lee.

Molts nodes de sortida es configuren per blocar certs tipus de trànsit per compartir fitxers, com ara BitTorrent. BitTorrent in particular is not anonymous over Tor.

Ara mateix, la longitud de la ruta està codificada a 3 punts més el nombre de nodes sensibles de la vostra ruta. És a dir, en casos normals és de 3, però per exemple si accediu a un servei de onion o una adreça ".exit", podria ser més.

No volem encoratjar a les persones a utilitzar trajectes més llargs que això, ja que augmenta la càrrega a la xarxa sense (en la mesura que podem dir) que proporcioni més seguretat. A més, l'ús de rutes de més de 3 pot fer malbé l'anonimat, primer, perquè facilita els atacs de denegació de seguretat i, en segon lloc, perquè podria actuar com a identificador si només un petit nombre d'usuaris tenen la mateixa longitud de camí.

No hi ha res que els desenvolupadors de Tor puguin fer per rastrejar els usuaris de Tor. Les mateixes proteccions que eviten que les persones dolentes frenin l'anonimat de Tor també ens impedeix rastrejar els usuaris.

There are a few reasons we don't:

  1. We can't help but make the information available, since Tor clients need to use it to pick their paths. So if the "blockers" want it, they can get it anyway. Further, even if we didn't tell clients about the list of relays directly, somebody could still make a lot of connections through Tor to a test site and build a list of the addresses they see.
  2. If people want to block us, we believe that they should be allowed to do so. Obviously, we would prefer for everybody to allow Tor users to connect to them, but people have the right to decide who their services should allow connections from, and if they want to block anonymous users, they can.
  3. Being blockable also has tactical advantages: it may be a persuasive response to website maintainers who feel threatened by Tor. Giving them the option may inspire them to stop and think about whether they really want to eliminate private access to their system, and if not, what other options they might have. The time they might otherwise have spent blocking Tor, they may instead spend rethinking their overall approach to privacy and anonymity.

Even if your application is using the correct variant of the SOCKS protocol, there is still a risk that it could be leaking DNS queries. This problem happens in Firefox extensions that resolve the destination hostname themselves, for example to show you its IP address, what country it's in, etc. If you suspect your application might behave like this, follow the instructions below to check.

  1. Add TestSocks 1 to your torrc file.
  2. Start Tor, and point your program's SOCKS proxy settings to Tor's SOCKS5 server (socks5://127.0.0.1:9050 by default).
  3. Watch your logs as you use your application. For each socks connection, Tor will log a notice for safe connections, and a warn for connections leaking DNS requests.

If you want to automatically disable all connections leaking DNS requests, set SafeSocks 1 in your torrc file.

El Tor es recolza en el suport d'usuaris i voluntaris d'arreu del món per a ajudar-nos a millorar el nostre programari i recursos. Així doncs, apreciem molt els vostres comentaris (nosaltres i tots els usuaris del Tor).

Feedback template

When sending us feedback or reporting a bug, please include as many of these as possible:

  • Operating System you are using
  • Tor Browser version
  • Tor Browser Security Level
  • Step by step of how you got to the issue, so we can reproduce it (e.g. I opened the browser, typed a url, clicked on (i) icon, then my browser crashed)
  • A screenshot of the problem
  • The log

How to Reach Us

There are several ways to reach us, so please use what works best for you.

GitLab

First, check if the bug is already known. You can search and read all the issues at https://gitlab.torproject.org/. To create a new issue, please request a new account to access Tor Project's GitLab instance and find the right repository to report your issue. We track all Tor Browser related issues at Tor Browser issue tracker. Issues related to our websites should be filed under the Web issue tracker.

Email

Send us an email to frontdesk@torproject.org

In the subject line of your email, please tell us what you're reporting. The more specific your subject line is (e.g. "Connection failure", "feedback on website", "feedback on Tor Browser, "I need a bridge"), the easier it will be for us to understand and follow up. Sometimes when we receive emails without subject lines, they're marked as spam and we don't see them.

For the fastest response, please write in English, Spanish, and/or Portuguese if you can. If none of these languages works for you, please write in any language you feel comfortable with, but keep in mind it will take us a bit longer to answer as we will need help with translation to understand it.

Blog post comments

You can always leave comments on the blog post related to the issue or feedback you want to report. If there is not a blog post related to your issue, please contact us another way.

IRC

You can find us in the #tor channel on OFTC to give us feedback or report bugs/issues. We may not respond right away, but we do check the backlog and will get back to you when we can.

Learn how to connect to OFTC servers.

Email Lists

For reporting issues or feedback using email lists, we recommend that you do so on the one that is related to what you would like to report. A complete directory of our mailing lists can be found here.

For feedback or issues related to Tor Browser, Tor network or other projects developed by Tor: tor-talk

For feedback or issues related to our websites: ux

For feedback or issues related to running a Tor relay: tor-relays

For feedback on content related to Tor Browser Manual or Support website: tor-community-team

Report a security issue

If you've found a security issue in one of our projects or in our infrastructure, please email tor-security@lists.torproject.org. If you've found a security bug in Tor or Tor Browser, feel free to submit it for our bug bounty program. Si voleu xifrar el vostre correu, podeu obtenir la clau GPG pública de la llista si contacteu amb tor-security-sendkey@lists.torproject.org o des de pool.sks-keyservers.net. Aquí teniu l'empremta:

  gpg --fingerprint tor-security@lists.torproject.org
  pub 4096R/1A7BF184 2017-03-13
  Key fingerprint = 8B90 4624 C5A2 8654 E453 9BC2 E135 A8B4 1A7B F184
  uid tor-security@lists.torproject.org
  uid tor-security@lists.torproject.org
  uid tor-security@lists.torproject.org
  sub 4096R/C00942E4 2017-03-13

Contacte

The #tor-project channel is where Tor people discuss and coordinate daily Tor work. It has fewer members than #tor and is more focused on the work at hand. You are also welcome to join this channel. To access #tor-project, your nickname (nick) must be registered and verified.

Here's how to reach #tor-project and other registered channels.

Register your nickname

  1. Log onto #tor. See How can I chat with Tor Project teams?

  2. Then, click on the word "Status" at the top left of the screen.

  3. In the window at the bottom of the page, type: /msg nickserv REGISTER yournewpassword youremailaddress

  4. Hit enter.

If all goes well, you will receive a message that you are registered.

The system may register you as your nick_ instead of your nick.

If so, just go with it but remember you are user_ and not user.

Every time you log on to IRC, to identify your registered nick, type:

/nick yournick

/msg nickserv IDENTIFY YourPassWord

How to verify your nickname

After registering your nickname, to gain access to the #tor-project and other protected channels, your nickname must be verified.

  1. Go to https://services.oftc.net/ and follow the steps in the 'To verify your account' section

  2. Go back to the IRC webpage where you are logged in and type:

    /msg nickserv checkverify

  3. Click ENTER.

  4. If all is well, you will receive a message that says:

*!NickServ*checkverify

Usermodechange: +R

!NickServ- Successfully set +R on your nick.
`

Your nick is verified!

Now, to join #tor-project, you can just type:

/join #tor-project and hit enter.

You will be allowed into the channel. If so, Congratulations!

However, if you get stuck, you can ask for help in the #tor channel.

You can toggle back and forth between channels by clicking on the different channel names at the top left of the IRC window.

Here is how you can get onto IRC and start to chat with Tor contributors in real time:

  1. Enter in OFTC webchat.

  2. Fill in the blanks:

    NICKNAME: Anything you want, but choose the same nickname (nick) every time you use IRC to talk to people on Tor. If your nick is already being used, you will get a message from the system and you should choose another nick.

    CHANNEL: #tor

  3. Click Enter

Congratulations! You're on IRC.

After a few seconds, you will automatically enter #tor, which is a chatroom with Tor developers, relay operators and other community members. There are some random people in #tor as well.

You can ask questions in the empty bar at the bottom of the screen. Please, don't ask to ask, just ask your question.

People may be able to answer right away, or there may be a bit of a delay (some people are listed on the channel but are away from their keyboards and record channel activities to read later).

If you want to chat with someone specific, start your comment with their nick and they will typically receive a notification that someone is trying to contact them.

OFTC often doesn't allow people to use their webchat over Tor. For this reason, and because many people end up preferring it anyway, you should also consider using an IRC client.

El Tor es recolza en el suport d'usuaris i voluntaris d'arreu del món per a ajudar-nos a millorar el nostre programari i recursos. Així doncs, apreciem molt els vostres comentaris (nosaltres i tots els usuaris del Tor).

Feedback template

When sending us feedback or reporting a bug, please include as many of these as possible:

  • Operating System you are using
  • Tor Browser version
  • Tor Browser Security Level
  • Step by step of how you got to the issue, so we can reproduce it (e.g. I opened the browser, typed a url, clicked on (i) icon, then my browser crashed)
  • A screenshot of the problem
  • The log

How to Reach Us

There are several ways to reach us, so please use what works best for you.

GitLab

First, check if the bug is already known. You can search and read all the issues at https://gitlab.torproject.org/. To create a new issue, please request a new account to access Tor Project's GitLab instance and find the right repository to report your issue. We track all Tor Browser related issues at Tor Browser issue tracker. Issues related to our websites should be filed under the Web issue tracker.

Email

Send us an email to frontdesk@torproject.org

In the subject line of your email, please tell us what you're reporting. The more specific your subject line is (e.g. "Connection failure", "feedback on website", "feedback on Tor Browser, "I need a bridge"), the easier it will be for us to understand and follow up. Sometimes when we receive emails without subject lines, they're marked as spam and we don't see them.

For the fastest response, please write in English, Spanish, and/or Portuguese if you can. If none of these languages works for you, please write in any language you feel comfortable with, but keep in mind it will take us a bit longer to answer as we will need help with translation to understand it.

Blog post comments

You can always leave comments on the blog post related to the issue or feedback you want to report. If there is not a blog post related to your issue, please contact us another way.

IRC

You can find us in the #tor channel on OFTC to give us feedback or report bugs/issues. We may not respond right away, but we do check the backlog and will get back to you when we can.

Learn how to connect to OFTC servers.

Email Lists

For reporting issues or feedback using email lists, we recommend that you do so on the one that is related to what you would like to report. A complete directory of our mailing lists can be found here.

For feedback or issues related to Tor Browser, Tor network or other projects developed by Tor: tor-talk

For feedback or issues related to our websites: ux

For feedback or issues related to running a Tor relay: tor-relays

For feedback on content related to Tor Browser Manual or Support website: tor-community-team

Report a security issue

If you've found a security issue in one of our projects or in our infrastructure, please email tor-security@lists.torproject.org. If you've found a security bug in Tor or Tor Browser, feel free to submit it for our bug bounty program. Si voleu xifrar el vostre correu, podeu obtenir la clau GPG pública de la llista si contacteu amb tor-security-sendkey@lists.torproject.org o des de pool.sks-keyservers.net. Aquí teniu l'empremta:

  gpg --fingerprint tor-security@lists.torproject.org
  pub 4096R/1A7BF184 2017-03-13
  Key fingerprint = 8B90 4624 C5A2 8654 E453 9BC2 E135 A8B4 1A7B F184
  uid tor-security@lists.torproject.org
  uid tor-security@lists.torproject.org
  uid tor-security@lists.torproject.org
  sub 4096R/C00942E4 2017-03-13

Repositori Debian

No. Do not use the packages in Ubuntu's universe. In the past they have not been reliably updated. That means you could be missing stability and security fixes. Instead, please use Tor Debian repository.

The Tor Project maintains its own Debian package repository. Since Debian provides the LTS version of Tor, this might not always give you the latest stable Tor version. Therefore, it's recommended to install tor from our repository.

Here's how you can enable Tor Package Repository in Debian based distributions:

Note: The symbol # refers to running the code as root. This means you should have access to a user account with system administration privileges, e.g your user should be in the sudo group.

Prerequisite: Verify the CPU architecture

The package repository offers amd64, arm64, and i386 binaries. Verify your operating system is capable of running the binary by inspecting the output of the following commend:

  ‪# dpkg --print-architecture

It should output either amd64, arm64, or i386. The repository does not support other CPU architectures.

Note on Raspbian: The package repository does not offer 32-bit ARM architecture (armhf) images. You should either build Tor from source, or install the version Debian offers.

1. Install apt-transport-https

To enable all package managers using the libapt-pkg library to access metadata and packages available in sources accessible over https (Hypertext Transfer Protocol Secure).

   ‪# apt install apt-transport-https

2. Create a new file in /etc/apt/sources.list.d/ named tor.list. Add the following entries:

   deb     [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org <DISTRIBUTION> main
   deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org <DISTRIBUTION> main

If you want to try experimental packages, add these in addition to the lines from above (Note, use whatever is the current experimental version instead of 0.4.6.x from the example below):

   deb     [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org tor-experimental-0.4.6.x-<DISTRIBUTION> main
   deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org tor-experimental-0.4.6.x-<DISTRIBUTION> main

Or nightly builds:

   deb     [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org tor-nightly-master-<DISTRIBUTION> main
   deb-src [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org tor-nightly-master-<DISTRIBUTION> main

Replace <DISTRIBUTION> with your Operating System codename. Run lsb_release -c or cat /etc/debian_version to check the Operating System version.

Note: Ubuntu Focal dropped support for 32-bit, so instead use:

   deb     [arch=amd64 signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org focal main
   deb-src [arch=amd64 signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org focal main

Warning symptom, when running sudo apt update:

   Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'http://deb.torproject.org/torproject.org focal InRelease' doesn't support architecture 'i386'

3. Then add the gpg key used to sign the packages by running the following command at your command prompt:

   ‪# wget -O- https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --dearmor | tee /usr/share/keyrings/tor-archive-keyring.gpg >/dev/null

4. Install tor and tor debian keyring

We provide a Debian package to help you keep our signing key current. It is recommended you use it. Install it with the following commands:

   ‪# apt update
   ‪# apt install tor deb.torproject.org-keyring

Yes, deb.torproject.org is also served through via an Onion Service: http://apow7mjfryruh65chtdydfmqfpj5btws7nbocgtaovhvezgccyjazpqd.onion/

Note: The symbol # refers to running the code as root. This means you should have access to a user account with system administration privileges, e.g your user should be in the sudo group.

To use Apt over Tor, the apt transport needs to be installed:

   ‪# apt install apt-transport-tor

Then you need to add the following entries to /etc/apt/sources.list or a new file in /etc/apt/sources.list.d/:

   # For the stable version.
   deb tor://apow7mjfryruh65chtdydfmqfpj5btws7nbocgtaovhvezgccyjazpqd.onion/torproject.org <DISTRIBUTION> main

   # For the unstable version.
   deb tor://apow7mjfryruh65chtdydfmqfpj5btws7nbocgtaovhvezgccyjazpqd.onion/torproject.org tor-nightly-master-<DISTRIBUTION> main

Replace <DISTRIBUTION> with your Operating System codename. Run lsb_release -c or cat /etc/debian_version to check the Operating System version.

Now refresh your sources and try to install tor again:

   ‪# apt update
   ‪# apt install tor

Tor rpm packages

The Tor Project maintains its own RPM package repository for CentOS and RHEL and Fedora.

Note: The symbol # refers to be running the code as root. That means you should have access to a user account with system administration privileges, e.g your user should be in the sudo group.

Here's how you can enable Tor Package Repository for both CentOS and RHEL and Fedora:

1. Enable epel repository (only for CentOS and RHEL)

‪# dnf install epel-release -y

2. Add the following to /etc/yum.repos.d/tor.repo

For CentOS or RHEL:

[tor]
name=Tor for Enterprise Linux $releasever - $basearch
baseurl=https://rpm.torproject.org/centos/$releasever/$basearch
enabled=1
gpgcheck=1
gpgkey=https://rpm.torproject.org/centos/public_gpg.key
cost=100

For Fedora:

[tor]
name=Tor for Fedora $releasever - $basearch
baseurl=https://rpm.torproject.org/fedora/$releasever/$basearch
enabled=1
gpgcheck=1
gpgkey=https://rpm.torproject.org/fedora/public_gpg.key
cost=100

3. Install the Tor package

Then you can install the latest Tor package.

‪# dnf install tor -y

Using it for the first time, you will have to import the GPG public key.

Importing GPG key 0x3621CD35:
Userid     : "Kushal Das (RPM Signing key) <kushal@torproject.org>"
Fingerprint: 999E C8E3 14BC 8D46 022D 6C7D E217 C30C 3621 CD35
From       : https://rpm.torproject.org/fedora/public_gpg.key
Is this ok [y/N]: y

Abuse FAQ

Great. That's exactly why we implemented exit policies.

Each Tor relay has an exit policy that specifies what sort of outbound connections are allowed or refused from that relay. The exit policies are propagated to Tor clients via the directory, so clients will automatically avoid picking exit relays that would refuse to exit to their intended destination. This way each relay can decide the services, hosts, and networks it wants to allow connections to, based on abuse potential and its own situation. Read the Support entry on issues you might encounter if you use the default exit policy, and then read Mike Perry's tips for running an exit node with minimal harassment.

The default exit policy allows access to many popular services (e.g. web browsing), but restricts some due to abuse potential (e.g. mail) and some since the Tor network can't handle the load (e.g. default file-sharing ports). You can change your exit policy by editing your torrc file. If you want to avoid most if not all abuse potential, set it to "reject *:*". This setting means that your relay will be used for relaying traffic inside the Tor network, but not for connections to external websites or other services.

If you do allow any exit connections, make sure name resolution works (that is, your computer can resolve Internet addresses correctly). If there are any resources that your computer can't reach (for example, you are behind a restrictive firewall or content filter), please explicitly reject them in your exit policy otherwise Tor users will be impacted too.

Criminals can already do bad things. Since they're willing to break laws, they already have lots of options available that provide better privacy than Tor provides. They can steal cell phones, use them, and throw them in a ditch; they can crack into computers in Korea or Brazil and use them to launch abusive activities; they can use spyware, viruses, and other techniques to take control of literally millions of Windows machines around the world.

Tor aims to provide protection for ordinary people who want to follow the law. Only criminals have privacy right now, and we need to fix that.

Some advocates of anonymity explain that it's just a tradeoff — accepting the bad uses for the good ones — but there's more to it than that. Criminals and other bad people have the motivation to learn how to get good anonymity, and many have the motivation to pay well to achieve it. Being able to steal and reuse the identities of innocent victims (identity theft) makes it even easier. Normal people, on the other hand, don't have the time or money to spend figuring out how to get privacy online. This is the worst of all possible worlds.

So yes, criminals can use Tor, but they already have better options, and it seems unlikely that taking Tor away from the world will stop them from doing their bad things. At the same time, Tor and other privacy measures can fight identity theft, physical crimes like stalking, and so on.

Distributed denial of service (DDoS) attacks typically rely on having a group of thousands of computers all sending floods of traffic to a victim. Since the goal is to overpower the bandwidth of the victim, they typically send UDP packets since those don't require handshakes or coordination.

But because Tor only transports correctly formed TCP streams, not all IP packets, you cannot send UDP packets over Tor. (You can't do specialized forms of this attack like SYN flooding either.) So ordinary DDoS attacks are not possible over Tor. Tor also doesn't allow bandwidth amplification attacks against external sites: you need to send in a byte for every byte that the Tor network will send to your destination. So in general, attackers who control enough bandwidth to launch an effective DDoS attack can do it just fine without Tor.

First of all, the default Tor exit policy rejects all outgoing port 25 (SMTP) traffic. So sending spam mail through Tor isn't going to work by default. It's possible that some relay operators will enable port 25 on their particular exit node, in which case that computer will allow outgoing mails; but that individual could just set up an open mail relay too, independent of Tor. In short, Tor isn't useful for spamming, because nearly all Tor relays refuse to deliver the mail.

Of course, it's not all about delivering the mail. Spammers can use Tor to connect to open HTTP proxies (and from there to SMTP servers); to connect to badly written mail-sending CGI scripts; and to control their botnets — that is, to covertly communicate with armies of compromised computers that deliver the spam.

This is a shame, but notice that spammers are already doing great without Tor. Also, remember that many of their more subtle communication mechanisms (like spoofed UDP packets) can't be used over Tor, because it only transports correctly-formed TCP connections.

Not much, in the grand scheme of things. The network has been running since October 2003, and it's only generated a handful of complaints. Of course, like all privacy-oriented networks on the net, it attracts its share of jerks. Tor's exit policies help separate the role of "willing to donate resources to the network" from the role of "willing to deal with exit abuse complaints", so we hope our network is more sustainable than past attempts at anonymity networks.

Since Tor has many good uses as well, we feel that we're doing pretty well at striking a balance currently.

If you run a Tor relay that allows exit connections (such as the default exit policy), it's probably safe to say that you will eventually hear from somebody. Abuse complaints may come in a variety of forms. For example:

  • Somebody connects to Hotmail, and sends a ransom note to a company. The FBI sends you a polite email, you explain that you run a Tor relay, and they say "oh well" and leave you alone. [Port 80]
  • Somebody tries to get you shut down by using Tor to connect to Google groups and post spam to Usenet, and then sends an angry mail to your ISP about how you're destroying the world. [Port 80]
  • Somebody connects to an IRC network and makes a nuisance of himself. Your ISP gets polite mail about how your computer has been compromised; and/or your computer gets DDoSed. [Port 6667]
  • Somebody uses Tor to download a Vin Diesel movie, and your ISP gets a DMCA takedown notice. See EFF's Tor DMCA Response Template, which explains why your ISP can probably ignore the notice without any liability. [Arbitrary ports]

Some hosting providers are friendlier than others when it comes to Tor exits. For a listing see the good and bad ISPs wiki.

For a complete set of template responses to different abuse complaint types, see the collection of templates. You can also proactively reduce the amount of abuse you get by following these tips for running an exit node with minimal harassment and running a reduced exit policy.

You might also find that your Tor relay's IP is blocked from accessing some Internet sites/services. This might happen regardless of your exit policy, because some groups don't seem to know or care that Tor has exit policies. (If you have a spare IP not used for other activities, you might consider running your Tor relay on it.) In general, it's advisable not to use your home internet connection to provide a Tor relay.

Sometimes jerks make use of Tor to troll IRC channels. This abuse results in IP-specific temporary bans ("klines" in IRC lingo), as the network operators try to keep the troll off of their network.

This response underscores a fundamental flaw in IRC's security model: they assume that IP addresses equate to humans, and by banning the IP address they can ban the human. In reality, this is not the case — many such trolls routinely make use of the literally millions of open proxies and compromised computers around the Internet. The IRC networks are fighting a losing battle of trying to block all these nodes, and an entire cottage industry of blocklists and counter-trolls has sprung up based on this flawed security model (not unlike the antivirus industry). The Tor network is just a drop in the bucket here.

On the other hand, from the viewpoint of IRC server operators, security is not an all-or-nothing thing. By responding quickly to trolls or any other social attack, it may be possible to make the attack scenario less attractive to the attacker. And most individual IP addresses do equate to individual humans, on any given IRC network at any given time. The exceptions include NAT gateways which may be allocated access as special cases. While it's a losing battle to try to stop the use of open proxies, it's not generally a losing battle to keep klining a single ill-behaved IRC user until that user gets bored and goes away.

But the real answer is to implement application-level auth systems, to let in well-behaving users and keep out badly-behaving users. This needs to be based on some property of the human (such as a password they know), not some property of the way their packets are transported.

Of course, not all IRC networks are trying to ban Tor nodes. After all, quite a few people use Tor to IRC in privacy in order to carry on legitimate communications without tying them to their real-world identity. Each IRC network needs to decide for itself if blocking a few more of the millions of IPs that bad people can use is worth losing the contributions from the well-behaved Tor users.

If you're being blocked, have a discussion with the network operators and explain the issues to them. They may not be aware of the existence of Tor at all, or they may not be aware that the hostnames they're klining are Tor exit nodes. If you explain the problem, and they conclude that Tor ought to be blocked, you may want to consider moving to a network that is more open to free speech. Maybe inviting them to #tor on irc.oftc.net will help show them that we are not all evil people.

Finally, if you become aware of an IRC network that seems to be blocking Tor, or a single Tor exit node, please put that information on The Tor IRC block tracker so that others can share. At least one IRC network consults that page to unblock exit nodes that have been blocked inadvertently.

Even though Tor isn't useful for spamming, some over-zealous blocklisters seem to think that all open networks like Tor are evil — they attempt to strong-arm network administrators on policy, service, and routing issues, and then extract ransoms from victims.

If your server administrators decide to make use of these blocklists to refuse incoming mail, you should have a conversation with them and explain about Tor and Tor's exit policies.

We're sorry to hear that. There are some situations where it makes sense to block anonymous users for an Internet service. But in many cases, there are easier solutions that can solve your problem while still allowing users to access your website securely.

First, ask yourself if there's a way to do application-level decisions to separate the legitimate users from the jerks. For example, you might have certain areas of the site, or certain privileges like posting, available only to people who are registered. It's easy to build an up-to-date list of Tor IP addresses that allow connections to your service, so you could set up this distinction only for Tor users. This way you can have multi-tiered access and not have to ban every aspect of your service.

For example, the Freenode IRC network had a problem with a coordinated group of abusers joining channels and subtly taking over the conversation; but when they labeled all users coming from Tor nodes as "anonymous users", removing the ability of the abusers to blend in, the abusers moved back to using their open proxies and bot networks.

Second, consider that hundreds of thousands of people use Tor every day simply for good data hygiene — for example, to protect against data-gathering advertising companies while going about their normal activities. Others use Tor because it's their only way to get past restrictive local firewalls. Some Tor users may be legitimately connecting to your service right now to carry on normal activities. You need to decide whether banning the Tor network is worth losing the contributions of these users, as well as potential future legitimate users. (Often people don't have a good measure of how many polite Tor users are connecting to their service — you never notice them until there's an impolite one.)

At this point, you should also ask yourself what you do about other services that aggregate many users behind a few IP addresses. Tor is not so different from AOL in this respect.

Lastly, please remember that Tor relays have individual exit policies. Many Tor relays do not allow exiting connections at all. Many of those that do allow some exit connections might already disallow connections to your service. When you go about banning nodes, you should parse the exit policies and only block the ones that allow these connections; and you should keep in mind that exit policies can change (as well as the overall list of nodes in the network).

If you really want to do this, we provide a Tor exit relay list or a DNS-based list you can query.

(Some system administrators block ranges of IP addresses because of official policy or some abuse pattern, but some have also asked about allowing Tor exit relays because they want to permit access to their systems only using Tor. These scripts are usable for allowlisting as well.)

No hi ha res que els desenvolupadors de Tor puguin fer per rastrejar els usuaris de Tor. The same protections that keep bad people from breaking Tor's anonymity also prevent us from figuring out what's going on.

Some fans have suggested that we redesign Tor to include a backdoor. There are two problems with this idea. First, it technically weakens the system too far. Having a central way to link users to their activities is a gaping hole for all sorts of attackers; and the policy mechanisms needed to ensure correct handling of this responsibility are enormous and unsolved. Second, the bad people aren't going to get caught by this anyway, since they will use other means to ensure their anonymity (identity theft, compromising computers and using them as bounce points, etc).

This ultimately means that it is the responsibility of site owners to protect themselves against compromise and security issues that can come from anywhere. This is just part of signing up for the benefits of the Internet. You must be prepared to secure yourself against the bad elements, wherever they may come from. Tracking and increased surveillance are not the answer to preventing abuse.

But remember that this doesn't mean that Tor is invulnerable. Traditional police techniques can still be very effective against Tor, such as investigating means, motive, and opportunity, interviewing suspects, writing style analysis, technical analysis of the content itself, sting operations, keyboard taps, and other physical investigations. The Tor Project is also happy to work with everyone including law enforcement groups to train them how to use the Tor software to safely conduct investigations or anonymized activities online.

The Tor Project does not host, control, nor have the ability to discover the owner or location of a .onion address. The .onion address is an address from an onion service. The name you see ending in .onion is an onion service descriptor. It's an automatically generated name which can be located on any Tor relay or client anywhere on the Internet. Onion services are designed to protect both the user and service provider from discovering who they are and where they are from. The design of onion services means the owner and location of the .onion site is hidden even from us.

But remember that this doesn't mean that onion services are invulnerable. Traditional police techniques can still be very effective against them, such as interviewing suspects, writing style analysis, technical analysis of the content itself, sting operations, keyboard taps, and other physical investigations.

If you have a complaint about child abuse materials, you may wish to report it to the National Center for Missing and Exploited Children, which serves as a national coordination point for investigation of child pornography: http://www.missingkids.com/. We do not view links you report.

We take abuse seriously. Activists and law enforcement use Tor to investigate abuse and help support survivors. We work with them to help them understand how Tor can help their work. In some cases, technological mistakes are being made and we help to correct them. Because some people in survivors' communities embrace stigma instead of compassion, seeking support from fellow victims requires privacy-preserving technology.

Our refusal to build backdoors and censorship into Tor is not because of a lack of concern. We refuse to weaken Tor because it would harm efforts to combat child abuse and human trafficking in the physical world, while removing safe spaces for victims online. Meanwhile, criminals would still have access to botnets, stolen phones, hacked hosting accounts, the postal system, couriers, corrupt officials, and whatever technology emerges to trade content. They are early adopters of technology. In the face of this, it is dangerous for policymakers to assume that blocking and filtering is sufficient. We are more interested in helping efforts to halt and prevent child abuse than helping politicians score points with constituents by hiding it. The role of corruption is especially troubling; see this United Nations report on The Role of Corruption in Trafficking in Persons.

Finally, it is important to consider the world that children will encounter as adults when enacting policy in their name. Will they thank us if they are unable to voice their opinions safely as adults? What if they are trying to expose a failure of the state to protect other children?

Tor Metrics

We actually don't count users, but we count requests to the directories that clients make periodically to update their list of relays and estimate number of users indirectly from there.

No, but we can see what fraction of directories reported them, and then we can extrapolate the total number in the network.

We put in the assumption that the average client makes 10 such requests per day. A tor client that is connected 24/7 makes about 15 requests per day, but not all clients are connected 24/7, so we picked the number 10 for the average client. We simply divide directory requests by 10 and consider the result as the number of users. Another way of looking at it, is that we assume that each request represents a client that stays online for one tenth of a day, so 2 hours and 24 minutes.

Average number of concurrent users, estimated from data collected over a day. We can't say how many distinct users there are.

No, the relays that report these statistics aggregate requests by country of origin and over a period of 24 hours. The statistics we would need to gather for the number of users per hour would be too detailed and might put users at risk.

Then we count those users as one. We really count clients, but it's more intuitive for most people to think of users, that's why we say users and not clients.

No, because that user updates their list of relays as often as a user that doesn't change IP address over the day.

The directories resolve IP addresses to country codes and report these numbers in aggregate form. This is one of the reasons why tor ships with a GeoIP database.

Very few bridges report data on transports or IP versions yet, and by default we consider requests to use the default OR protocol and IPv4. Once more bridges report these data, the numbers will become more accurate.

Relays and bridges report some of the data in 24-hour intervals which may end at any time of the day.
And after such an interval is over relays and bridges might take another 18 hours to report the data.
We cut off the last two days from the graphs, because we want to avoid that the last data point in a graph indicates a recent trend change which is in fact just an artifact of the algorithm.

The reason is that we publish user numbers once we're confident enough that they won't change significantly anymore. But it's always possible that a directory reports data a few hours after we were confident enough, but which then slightly changed the graph.

We do have descriptor archives from before that time, but those descriptors didn't contain all the data we use to estimate user numbers. Please find the following tarball for more details:

Tarball

For direct users, we include all directories which we didn't do in the old approach. We also use histories that only contain bytes written to answer directory requests, which is more precise than using general byte histories.

Oh, that's a whole different story. We wrote a 13 page long technical report explaining the reasons for retiring the old approach.
tl;dr: in the old approach we measured the wrong thing, and now we measure the right thing.

We run an anomaly-based censorship-detection system that looks at estimated user numbers over a series of days and predicts the user number in the next days. If the actual number is higher or lower, this might indicate a possible censorship event or release of censorship. For more details, see our technical report.

Little-t-tor

Attention: These instructions are to verify the tor source code. Please follow the right instructions to verify Tor Browser's signature.

La signatura digital és un procés que assegura que un paquet determinat ha estat generat pels seus desenvolupadors i no ha estat alterat. Below we explain why it is important and how to verify that the tor source code you download is the one we have created and has not been modified by some attacker.

Each file on our download page is accompanied by a file labelled "sig" with the same name as the package and the extension ".asc". These .asc files are OpenPGP signatures. Això us permet verificar que el fitxer que esteu baixant és exactament el que heu demanat. This will vary by web browser, but generally you can download this file by right-clicking the "sig" link and selecting the "save file as" option.

For example, tor-0.4.6.7.tar.gz is accompanied by tor-0.4.6.7.tar.gz.asc. These are example file names and will not exactly match the file names that you download.

We now show how you can verify the downloaded file's digital signature on different operating systems. Please notice that a signature is dated the moment the package has been signed. Therefore every time a new file is uploaded a new signature is generated with a different date. As long as you have verified the signature you should not worry that the reported date may vary.

Installing GnuPG

First of all you need to have GnuPG installed before you can verify signatures.

For Windows users:

If you run Windows, download Gpg4win and run its installer.

In order to verify the signature you will need to type a few commands in windows command-line, cmd.exe.

Per a usuaris macOS:

If you are using macOS, you can install GPGTools.

In order to verify the signature you will need to type a few commands in the Terminal (under "Applications").

For GNU/Linux users:

If you are using GNU/Linux, then you probably already have GnuPG in your system, as most GNU/Linux distributions come with it preinstalled.

In order to verify the signature you will need to type a few commands in a terminal window. How to do this will vary depending on your distribution.

Fetching the Tor Developers key

Roger Dingledine (0xEB5A896A28988BF5 and 0xC218525819F78451), Nick Mathewson (0xFE43009C4607B1FB) sign Tor source tarballs.

Fetching Nick Mathewson most recent key:

‪$ gpg --auto-key-locate nodefault,wkd --locate-keys nickm@torproject.org

This should show you something like:

gpg: key FE43009C4607B1FB: public key "Nick Mathewson <nickm@torproject.org>" imported
gpg: Total number processed: 1
gpg:               imported: 1
pub   rsa4096 2016-09-21 [C] [expires: 2025-10-04]
      2133BC600AB133E1D826D173FE43009C4607B1FB
‪uid           [ unknown] Nick Mathewson <nickm@torproject.org>
sub   rsa4096 2016-09-23 [S] [expires: 2025-10-04]
sub   rsa4096 2016-09-23 [E] [expires: 2025-10-04]

If you get an error message, something has gone wrong and you cannot continue until you've figured out why this didn't work. You might be able to import the key using the Workaround (using a public key) section instead.

After importing the key, you can save it to a file (identifying it by its fingerprint here):

‪$ gpg --output ./tor.keyring --export 0x2133BC600AB133E1D826D173FE43009C4607B1FB

This command results in the key being saved to a file found at the path ./tor.keyring, i.e. in the current directory. If ./tor.keyring doesn't exist after running this command, something has gone wrong and you cannot continue until you've figured out why this didn't work.

Verifying the signature

To verify the signature of the package you downloaded, you will need to download the corresponding ".asc" signature file as well as the installer file itself, and verify it with a command that asks GnuPG to verify the file that you downloaded.

The examples below assume that you downloaded these two files to your "Downloads" folder. Note that these commands use example file names and yours will be different: you will have downloaded a different version than 9.0 and you may not have chosen the English (en-US) version.

For Windows users:

gpgv --keyring .\tor.keyring Downloads\tor-0.4.6.7.tar.gz.asc Downloads\tor-0.4.6.7.tar.gz

Per a usuaris macOS:

gpgv --keyring ./tor.keyring ~/Downloads/tor-0.4.6.7.tar.gz.asc ~/Downloads/tor-0.4.6.7.tar.gz

For GNU/Linux users:

gpgv --keyring ./tor.keyring ~/Downloads/tor-0.4.6.7.tar.gz.asc ~/Downloads/tor-0.4.6.7.tar.gz

The result of the command should produce something like this:

gpgv: Signature made Mon 16 Aug 2021 04:44:27 PM -03
gpgv:                using RSA key 7A02B3521DC75C542BA015456AFEE6D49E92B601
‪gpgv: Good signature from "Nick Mathewson <nickm@torproject.org>"

If you get error messages containing 'No such file or directory', either something went wrong with one of the previous steps, or you forgot that these commands use example file names and yours will be a little different.

Workaround (using a public key)

If you encounter errors you cannot fix, feel free to download and use this public key instead. Alternatively, you may use the following command:

‪$ curl -s https://openpgpkey.torproject.org/.well-known/openpgpkey/torproject.org/hu/kounek7zrdx745qydx6p59t9mqjpuhdf |gpg --import -

Nick Mathewson key is also available on keys.openpgp.org and can be downloaded from https://keys.openpgp.org/vks/v1/by-fingerprint/2133BC600AB133E1D826D173FE43009C4607B1FB.

If you're using macOS or GNU/Linux, the key can also be fetched by running the following command:

‪$ gpg --keyserver keys.openpgp.org --search-keys nickm@torproject.org

You may also want to learn more about GnuPG.

Alternate Designs We Don't Do (Yet)

This would be handy for a number of reasons: It would make Tor better able to handle new protocols like VoIP. It could solve the whole need to socksify applications. Exit relays would also not need to allocate a lot of file descriptors for all the exit connections.

We're heading in this direction. Some of the hard problems are:

  1. IP packets reveal OS characteristics. We would still need to do IP-level packet normalization, to stop things like TCP fingerprinting attacks. Given the diversity and complexity of TCP stacks, along with device fingerprinting attacks, it looks like our best bet is shipping our own user-space TCP stack.

  2. Application-level streams still need scrubbing. We will still need user-side applications like Torbutton. So it won't become just a matter of capturing packets and anonymizing them at the IP layer.

  3. Certain protocols will still leak information. For example, we must rewrite DNS requests so they are delivered to an unlinkable DNS server rather than the DNS server at a user's ISP; thus, we must understand the protocols we are transporting.

  4. DTLS (datagram TLS) basically has no users, and IPsec sure is big. Once we've picked a transport mechanism, we need to design a new end-to-end Tor protocol for avoiding tagging attacks and other potential anonymity and integrity issues now that we allow drops, resends, et cetera.

  5. Exit policies for arbitrary IP packets mean building a secure Intrusion Detection System (IDS). Our node operators tell us that exit policies are one of the main reasons they're willing to run Tor. Adding an IDS to handle exit policies would increase the security complexity of Tor, and would likely not work anyway, as evidenced by the entire field of IDS and counter-IDS papers. Many potential abuse issues are resolved by the fact that Tor only transports valid TCP streams (as opposed to arbitrary IP including malformed packets and IP floods.) Exit policies become even more important as we become able to transport IP packets. We also need to compactly describe exit policies in the Tor directory, so clients can predict which nodes will allow their packets to exit. Clients also need to predict all the packets they will want to send in a session before picking their exit node!

  6. The Tor-internal name spaces would need to be redesigned. We support onion service ".onion" addresses by intercepting the addresses when they are passed to the Tor client. Doing so at the IP level will require a more complex interface between Tor and the local DNS resolver.

Requiring every Tor user to be a relay would help with scaling the network to handle all our users, and running a Tor relay may help your anonymity. However, many Tor users cannot be good relays — for example, some Tor clients operate from behind restrictive firewalls, connect via modem, or otherwise aren't in a position where they can relay traffic. Providing service to these clients is a critical part of providing effective anonymity for everyone, since many Tor users are subject to these or similar constraints and including these clients increases the size of the anonymity set.

That said, we do want to encourage Tor users to run relays, so what we really want to do is simplify the process of setting up and maintaining a relay. We've made a lot of progress with easy configuration in the past few years: Tor is good at automatically detecting whether it's reachable and how much bandwidth it can offer.

There are four steps we need to address before we can do this though:

  • First, we still need to get better at automatically estimating the right amount of bandwidth to allow. It might be that switching to UDP transport is the simplest answer here — which alas is not a very simple answer at all.

  • Second, we need to work on scalability, both of the network (how to stop requiring that all Tor relays be able to connect to all Tor relays) and of the directory (how to stop requiring that all Tor users know about all Tor relays). Changes like this can have large impact on potential and actual anonymity. See Section 5 of the Challenges paper for details. Again, UDP transport would help here.

  • Third, we need to better understand the risks from letting the attacker send traffic through your relay while you're also initiating your own anonymized traffic. Three different research papers describe ways to identify the relays in a circuit by running traffic through candidate relays and looking for dips in the traffic while the circuit is active. These clogging attacks are not that scary in the Tor context so long as relays are never clients too. But if we're trying to encourage more clients to turn on relay functionality too (whether as bridge relays or as normal relays), then we need to understand this threat better and learn how to mitigate it.

  • Fourth, we might need some sort of incentive scheme to encourage people to relay traffic for others, and/or to become exit nodes. Here are our current thoughts on Tor incentives.

Please help on all of these!

No, you cannot trust the network to pick the path. Malicious relays could route you through their colluding friends. This would give an adversary the ability to watch all of your traffic end to end.

It would be nice to let relay operators say things like reject www.slashdot.org in their exit policies, rather than requiring them to learn all the IP address space that could be covered by the site (and then also blocking other sites at those IP addresses).

There are two problems, though. First, users could still get around these blocks. For example, they could request the IP address rather than the hostname when they exit from the Tor network. This means operators would still need to learn all the IP addresses for the destinations in question.

The second problem is that it would allow remote attackers to censor arbitrary sites. For example, if a Tor operator blocks www1.slashdot.org, and then some attacker poisons the Tor relay's DNS or otherwise changes that hostname to resolve to the IP address for a major news site, then suddenly that Tor relay is blocking the news site.