-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Matthew Toseland wrote: > * A node can get more than its fair share by just keeping connecting to > more and more nodes.
> * A node can get more than its fair share by pretending to be multiple > nodes. I completely agree - the new load balancing ideas were designed for a darknet, they are not Sybil-resistant. > So, what can be done? > - Reasonably strict tit-for-tat. If a node is not idle, then it should > only accept requests from nodes which are responding to its requests. As I've said before, I doubt tit-for-tat is useful (and it could even be harmful) unless there's a way to verify the responses to *all* messages. At the moment we can verify the responses to requests but not inserts, which put us between a rock and a hard place: * If we use tit-for-tat based on the number of requests and inserts the peer handles, it can send fake replies to inserts to increase its score * If we use tit-for-tat based only on the number of requests the peer handles, it can send fake replies to inserts in order to leave more bandwidth for handling requests - if enough nodes behave in this way it will be impossible to insert data If we can't find a way out of this dilemma I don't think tit-for-tat is viable. That in turn means we need to look elsewhere (in my opinion, to the darknet) for Sybil-resistance. > Of course we will need to allow a newbie node a small number of > requests initially. But if it is not able to serve some of our > requests, we should not serve its, after the first few. This is another well-known problem with tit-for-tat: you can only establish cooperation by cooperating early in the game. But without some limit on the creation of new identities, an attacker can just travel from node to node, exploiting the first-time cooperation of other nodes. Cheers, Michael -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) iD8DBQFEs1lxyua14OQlJ3sRAhBsAJsF92qI+gKMk73KCrZTyUxOgk/l1gCg4Bmj AwDfLG/763NNx7d3ZWUqIEU= =8mn5 -----END PGP SIGNATURE-----
