[[!meta title="Limitations of the Tor network"]]

Limitations of Tor

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Tails makes it clear that you are using Tor and probably Tails

Everything you do on the Internet from Tails goes through the Tor network.

Tor and Tails don't protect you by making you look like any random Internet user, but by making all Tor and Tails users look the same. It becomes impossible to know who is who among them.

Your Internet service provider (ISP) and local network can see that you connect to the Tor network. They still cannot know what sites you visit. To hide that you connect to Tor, you can use a [[Tor bridge|doc/anonymous_internet/tor]].

The sites that you visit can know that you are using Tor, because the <a href="https://metrics.torproject.org/exonerator.html">list of exit nodes of the Tor network</a> is public.

Parental controls, Internet service providers, and countries with heavy censorship can identify and block connections to the Tor network that don't use Tor bridges.

Many websites ask you to solve a CAPTCHA or block access from the Tor network.

Exit nodes can intercept traffic to the destination server

Tor hides your location from destination servers, but it does not encrypt <i>all</i> your communication. The last relay of a Tor circuit, called the <i>exit node</i>, establishes the actual connection to the destination server. This last step can be unencrypted, for example, if you connect to a website using HTTP instead of HTTPS.

The exit node can:

Observe your traffic. That is why <i>Tor Browser</i> and Tails include tools to encrypt the connection between the exit node and the destination server, whenever possible.

[[!img ssl_warning.png link=no alt="Warning: Potential Security Risk Ahead"]]

Adversaries watching both ends of a Tor circuit could identify users

An adversary, who could control the 3 relays in a circuit, could deanonymize Tor users.

Tor chooses 3 relays that belong to 3 different network operators for each circuit.

Tails takes extra measures to [[use different circuits for different applications|contribute/design/stream_isolation]].

The Tor network has more than 6&#8239;000 relays. Organizations running Tor relays include universities like the MIT, activist groups like Riseup, nonprofits like Derechos Digitales, Internet hosting companies like Private Internet Access, and so on. The huge diversity of people and organizations running Tor relays makes it more secure and more sustainable.