[GNUnet-developers] Trust vs. Reputation

[Ludovic Courtès]

Hi,

On Wed, Nov 24, 2004 at 02:31:40PM -0500, Christian Grothoff wrote:
> But this should not happen with GNUnet: even if you drop out for a while, 
> you're likely to reconnect to a similar set of peers, just because of your 
> local data/hosts cache.  Also I somehow doubt that we will have 100.000 
> (good) peers on-line at the same time anytime soon (especially since we 
> should only count peers that stay on-line for long periods here).  If you 
> have a network of say 10.000 peers and each peer has 50 connections (which is 
> more what I would expect a GNUnet network of that size would look like), 
> you're also likely to earn the trust of more peers at the same time (because 
> you have more connections).  So by the time you do some significant shifts in 
> your location (which, as I said should only happen very slowly anyway), 
> you're likely to have had the chance to establish some trust with a 
> significant fraction of the network which means it doesn't matter.

I must admit that even though I like GNUnet's model very much for it is
simple and "philosophically pleasant", I'm not that certain that their
assumptions are wrong.  Figure 5 shows that even with a relatively low
turnover and half of the nodes using GNUnet's model (the "private
history" scheme), the overall degree of cooperation falls to zero when
the system grows to between 100 and 1000 nodes only.  As nodes can't afford
maintaining a "trust level" for every node they talked to, the trust levels
they maintain are likely to become useless as they interact with more and
more nodes.

Moreover, as GNUnet gains wider acceptance and grows, one might as well
expect the turnover to increase I think.

Also, I don't understand what makes it so likely to "reconnect to a
similar set of peers".  If a node queries data which the peers it is
connected to don't have, it will _have to_ talk to other peers it may
not already know, won't it?

Thanks,
Ludovic.