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Is there any way to reduce the length of a hidden service's path to the rendezvous point?

  1. Bob's hidden service <---> Introduction Point
  2. Alice <---> Introduction Point tell Bob to contact me at Rendezvous Point
  3. Bob <-> Rendezvous point

Sometimes, Bob's hidden service does not need anonymity, but wants to be accessible via Tor anyways. (For example, ahmia.fi is also accessible as msydqstlz2kzerdg.onion). In such a case, it might be beneficial to limit the length of Bob's circuit to 1 (as indicated by the length of the arrow in step 3). Is that possible?

This is similar to How to decrease number of Tor hops?. and Accessing Tor hidden services over a single hop circuit, but those wanted to limit the number of client hops. This question is about the number of server hops.

Community
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serv-inc
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2 Answers2

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There are several amendments to Tor being researched to enable this functionality; the functionality does reduce/remove the anonymity of the server but sometimes that is okay, e.g. if (like Facebook) you run a publicly attested, non-hidden "onion service".*

The amendments are:

None of these are (at time of writing, January 2016) yet sedimented into the main Tor codebase, but they should be in the next few weeks/months.

As the above commenter almost suggests: you should consider carefully before enabling these features. From my experience running a publicly attested Onion, reduced server hop count does improve latency and makes Onion Services as performant, possibly a fraction more performant, than normal Tor. Your mileage may vary.

*Disclosure: I led the team which built the Facebook Onion Service

Jivan Pal
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Alec Muffett
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Never decrease the hop length, because it's a purpose of having Tor entry point : to be censorship-resistant. If you will decrease your hidden service behaviour, you will not just decrease it's anonymity, but also make connections to it "fingerprintable"=detectable, and - as a consecuence - censorable

Alexey Vesnin
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