On 07/03/12 20:05, James A. Donald wrote:

If I understand the proposed system http://www.ee.ucl.ac.uk/~mrio/papers/infocom09.pdf correctly:

Every entity has a public key.

Leechers issue IOUs to seeders. This creates a network of IOUs. The pledgeroute software looks for ways to cancel out IOUs, thus honoring them - for example Ann seeds Bob, Bob seeds Carol, and Carol seeds Ann.

If your IOUs get cancelled out, your key gains reputation, causing your IOUs to be valued.

It is not clear to me how the sybil attack is avoided: Is it that you only gain reputation with those benefiting from the cancellation?

If you consider a cluster of Sybils, the creator of the Sybils is free to create any structure of IOUs within the cluster, and any structure of IOUs from Sybils to non-Sybils. But IOUs from non-Sybils to Sybils can only be created by non-Sybils, and that only happens when the Sybils provide a service. No matter how many Sybils a person creates, the total debt owed to them by non-Sybils is limited by the total amount of service they provide. So there's no advantage in creating Sybils. It's not impossible - it's just pointless. I think that's how it works, anyway - it's been a while since I read the paper and I could be confusing it with the Sybilproof reputation mechanisms paper Matteo mentioned. Cheers, Michael _______________________________________________ p2p-hackers mailing list p2p-hackers@lists.zooko.com http://lists.zooko.com/mailman/listinfo/p2p-hackers ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE