[Nets-seminars] Talk (INFOCOM preparation) Thursday 2 April, 4pm GS/302

[Richard G. Clegg]

Don't forget tomorrow's talk -- the last before the easter break (note that 
this is Thursday, not the usual Friday).  Raul Landa will be presenting his 
INFOCOM paper "A Sybilproof Indirect Reciprocity Mechanism for Peer-to-Peer 
Networks".

For people who want to take a look either before the talk or after the talk 
a preprint is here: http://www.ee.ucl.ac.uk/%7Erlanda/infocom09.pdf

Abstract

Although direct reciprocity (Tit-for-Tat) contribution
systems have been successful in reducing freeloading in peerto-
peer overlays, it has been shown that, unless the contribution
network is dense, they tend to be slow (or may even fail) to
converge [1]. On the other hand, current indirect reciprocity
mechanisms based on reputation systems tend to be susceptible
to sybil attacks, peer slander and whitewashing.
In this paper we present PledgeRoute, an accounting mechanism
for peer contributions that is based on social capital.
This mechanism allows peers to contribute resources to one
set of peers and use this contribution to obtain services from
a different set of peers, at a different time. PledgeRoute is
completely decentralised, can be implemented in both structured
and unstructured peer-to-peer systems, and it is resistant to the
three kinds of attacks mentioned above.
To achieve this, we model contribution transitivity as a routing
problem in the contribution network of the peer-to-peer overlay,
and we present arguments for the routing behaviour and the
sybilproofness of our contribution transfer procedures on this
basis. Additionally, we present mechanisms for the seeding
of the contribution network, and a combination of incentive
mechanisms and reciprocation policies that motivate peers to
adhere to the protocol and maximise their service contributions
to the overlay.


-- 
Richard G. Clegg,
Dept of Elec. Eng.,
University College London
http://www.richardclegg.org/