[p2p-hackers] f2f for purposes other than privacy

[zooko at zooko.com]

 Ian Clarke wrote:
>
> We (Freenet) have
> been concerned about the fact that Freenet was harvestable for several
> years now.  Around spring this year I made the observation that if
> human relationships form a small world network, it should be possible
> to assign locations to people such that we form a Kleinberg-style
> small world network, and thus we could make the network routable.
> Oskar Sandberg then suggested a way to do this, and we set about
> validating the concept using simulations.

I would love to learn more.  Is there a white-paper or design document beyond
these slides from DefCon [1]?


> Are you aware of any current or proposed f2f
> networks for which concealment of user activity is not a goal?

Well, I think of the links between two friends in f2f to be not solely
communication channels but also to have other meaning.  For example, if friends
transmit music files to one another, then in addition to any privacy properties
that the network may have, it also serves as a decentralized, attack-resistant
recommendation engine for music.

Honestly, this area of research is ripe for exploration, but I can give you at
least a couple of examples.  Doceur set it up with a claimed general negative
result in "The Sybil Attack" in 2002 [2].  But his general negative result
isn't quite true, as disproven by e.g. Advogato, 2000 [3, 4, 5].  Recently
George Danezis, Chris Lesniewski-Laas, M. Frans Kaashoek, and Ross Anderson
smashed these two ideas together and mixed in some DHT routing: [6].

[6] is an excellent paper, which proposes a concrete DHT design and which
really nails the fact that the introduction graph or "bootstrap graph" contains
information which can defeat the allegedly undefeatable Sybil Attack.  [6]
references some related work which looks interesting, but I haven't followed
those links yet myself.  I guess [6] is somewhat relevant to the Freenet v0.7
design.

So, uh, anyway, this shows that there is interest in the notion of using
friendship networks for purposes other than privacy, namely attack resistance
of DHT routing and attack resistance of metadata [7 (self-citation)].

I think there's a lot more value to be mined from this concept, and I'm really
glad that it has finally gotten the attention of some p2p researchers.

Oh, and here's another perspective on this idea -- a post I wrote to my blog a
few years ago suggesting that all sorts of DHT innovations which were intended
to improve network performance could be applied to attack resistance: "trust is
just another topology" [8].

Regards,

Zooko

[1] http://freenetproject.org/papers/vegas1_dc.pdf
[2] http://citeseer.ist.psu.edu/douceur02sybil.html
[3] http://www.advogato.org/trust-metric.html
[4] http://www.levien.com/thesis/compact.pdf
[5] http://www.levien.com/free/tmetric-HOWTO.html
[6] http://pdos.csail.mit.edu/cgi-bin/pubs-date.cgi?match=Sybil-resistant+DHT+routing
[7] http://conferences.oreillynet.com/cs/p2p2001/view/e_sess/1200
[8] http://www.zooko.com/log-2003-01.html#d2003-01-23-trust_is_just_another_topology