Opened 4 years ago

Closed 7 months ago

#1855 closed project (implemented)

Compare datagram Tor designs

Reported by: arma Owned by: sjmurdoch
Priority: normal Milestone: Tor: unspecified
Component: Tor Version:
Keywords: tor-relay Cc: karsten
Actual Points: Parent ID:
Points:

Description (last modified by sjmurdoch)

A popular topic over the years has been moving from TCP transport between Tor relays to UDP transport, and then maybe switching to some congestion control approach that better recognizes the real endpoints in the communication.

We've been talking to Robert Watson and Bjoern A. Zeeb of the FreeBSD project about helping to fund them to port the FreeBSD network stack to user-space. Lately the user-space networking stack has seemed like the primary stumbling block.

We really ought to have a better intuition about what we're going to actually *do* once that stumbling block is resolved.

We should write a draft design doc and spec for a future version of Tor based on UDP transport. One main goal is to identify areas of uncertainty that need to be solved before such a system can be built and deployed. Another aspect of that goal is to identify and flesh out unsolved research questions, and pros and cons to various tradeoffs that designs like this have made. For example, should we do TCP-over-UDP pairwise, or end-to-end? Various research groups have very strong feelings, and often their recommendations conflict.

We might draw on six pieces of background work for ideas:

1) Joel Reardon's thesis:
http://freehaven.net/anonbib/#reardon-thesis

2) The old ZKS designs:
http://freehaven.net/anonbib/#freedom2-arch

3) Zach Brown's Cebolla:
http://freehaven.net/anonbib/#cebolla
http://www.cypherspace.org/cebolla/

4) Camilo Viecco's UDP-Tor design:
http://www.petsymposium.org/2008/hotpets/udp-tor.pdf

5) Csaba Kiraly's work:
http://disi.unitn.it/locigno/preprints/TR-DISI-08-041.pdf

6) Marc Liberatore's proposal 100:
https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/100-tor-spec-udp.txt

7) SHALON: Lightweight Anonymization based on Open Standards by Panchenko et al:
http://lorre.uni.lu/~andriy/papers/shalon-icccn09.pdf

The design should be sure to include a transition plan, and a plan for how to let clients who need blocking-resistance (e.g. they need to look like SSL on the wire) continue to use the network.

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Change History (20)

comment:1 Changed 4 years ago by arma

  • Description modified (diff)

comment:2 Changed 4 years ago by arma

  • Description modified (diff)

comment:3 Changed 4 years ago by arma

7) "SHALON: Lightweight Anonymization based on Open Standards" by Panchenko et al
http://www-i4.informatik.rwth-aachen.de/~andriy/papers/shalon-icccn09.pdf

comment:4 follow-up: Changed 3 years ago by arma

pde also points out djb's CurveCP:
http://curvecp.org/
which apparently is a TCP-like user-space stack with reasonable congestion control, per-packet confidentiality, and authentication. Wonder if it could play the role of pairwise TCP stacks + link encryption.

comment:5 in reply to: ↑ 4 Changed 3 years ago by arma

Replying to arma:

pde also points out djb's CurveCP:
http://curvecp.org/

pde also points to a bit of congestion control explanation for it at
http://www.cace-project.eu/downloads/deliverables-y2/CACE_D2.3_M24.pdf

comment:6 Changed 3 years ago by rransom

comment:7 Changed 3 years ago by nickm

  • Milestone Deliverable-Mar2011 deleted

comment:8 Changed 3 years ago by sjmurdoch

  • Owner set to sjmurdoch
  • Status changed from new to assigned

comment:9 Changed 3 years ago by nickm

  • Milestone set to Tor: unspecified

comment:10 Changed 3 years ago by sjmurdoch

  • Description modified (diff)

comment:11 Changed 3 years ago by sjmurdoch

  • Description modified (diff)
  • Status changed from assigned to accepted

comment:12 Changed 3 years ago by arma

  • Summary changed from Project: design for UDP transport to Project: comparison of datagram tor designs

comment:14 Changed 3 years ago by nickm

A good start; I'm interested in seeing how this develops.

comment:15 Changed 3 years ago by karsten

  • Summary changed from Project: comparison of datagram tor designs to Compare datagram Tor designs
  • Type changed from enhancement to project

comment:16 Changed 2 years ago by arma

  • Cc karsten added

Karsten, is this closeable now that we have a pdf? and maybe time for a new ticket to implement one of the approaches, e.g. the delay-based congestion control approach, and simulate it?

comment:17 Changed 2 years ago by karsten

Yes, sounds like it's safe to close this ticket now. I'm planning to make project tickets for all sponsor F year 2 deliverables and assign them to sponsor F milestones this week. I'll look out for existing tickets, like a ticket to implement one of the datagram approaches, and either turn them into project tickets or add them as child ticket to a project ticket.

comment:18 Changed 19 months ago by nickm

  • Keywords tor-relay added

comment:19 Changed 19 months ago by nickm

  • Component changed from Tor Relay to Tor

comment:20 Changed 7 months ago by arma

  • Resolution set to implemented
  • Status changed from accepted to closed
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