11

Being a LiveCD with no persistent storage by default, Tails currently does not use persistent Tor entry guards. In a recent post on the Tor blog, arma discussed the possibility of "improving Tor's anonymity" by increasing entry-guard persistence.

Is it dangerous to use Tails without persistent entry guards? From discussion on the Tails wiki, I gather that there's some tension between making entry guards persistent, and the ideal of complete amnesia. Is there unavoidable tension between being incognito and amnesiac?

  • 3
    You may probably need to rephrase your question to something like "What does it mean that Tails doesn't use Tor guard protection and how does it affect user?" – mrphs Oct 22 '13 at 10:34
  • Possibly with mentioning the latest Tails version that is known to be affected by this. It might change over time. "What does it mean that Tails releases up to $version doesn't use guards...?" – bastik Oct 22 '13 at 17:28
  • Without citation and context for that statement, this question is unanswerable. – mirimir Oct 23 '13 at 6:36
  • Persistence of entry guards is similarly problematic when anonymizing Bitcoins via Tor. While persistent entry guards do strengthen Tor against deanonymization, they also (in some small way, at least) fingerprint Tor clients. – mirimir Oct 23 '13 at 21:19
  • @mirimir I can't follow that. How do entry guards know you're using Bitcoin? Traffic fingerprinting somehow? Due to the size of the blockchain? And how could they link you to a specific Bitcoin address? – adrelanos Oct 23 '13 at 23:34
2

It depends on the threat model.

When one assumes an passive adversary keeping logs to which entry guards one is connecting to and when one plans to use Tor from different internet access points, it might be better to have non-persistent entry guards. This question Tracking User Location using Entry Guards? wheter this may or not be the case.

When one assumes an adversary hosting its own entry guards, it is safer to use persistent entry guards. Why? See question Why is a longer guard rotation period with fewer guards better than the other way around? and Peter Palfrader's answer.

The Tails developers have plans to implement persistent entry guards, see ticket. That ticket also contains additional extra information, such as a link to a discussion about a missing feature: Location-aware persistent guards. In an ideal world, users could enter a pin/token/password to choose various sets of entry guards (discussed in this Tor track ticket).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.