[freenet-dev] On Sybil Attacks

[Thomas Bruderer]

Hello devl-list

Since nearly two weeks I am working on my Master Thesis in Theoretical 
Computation. The topic is On sybil attacks on p2p systems, a bit general but I 
will focus on a simple abstraction of freenet.

nodes have a unique id
nodes can insert
nodes can request
nodes are in a small world
(maybe nodes can swap ids : enforcing swaps would be intersting theoretical 
topic too)

I think this are enough primitves to describe Freenet theoretically, if I am 
mising an important part, please enlight me,.




new primitives might be introduced to achieve the goal.

Maybe I'll do a small prove about 0.5 that sybil attacks are easy, but the focus
should be on the darknet, and maybe on the "Semi-Opennet"

I read the discussions about sybil-attacks in the board, and alread read some 
interesting Paper (I read douceurs paper first) I also read Ppaers about 
SybilGuard and Establishing Distinct Identities.

Its not as hopeless as it looks in the paper from douceur, and in the darknet 
model we have the premises about trusted links which are in fact a simple form 
of a CA. (we all know the Web Of Trust for X509 certificates, which tries to 
simulate a centralised Authority)

However also in Darknet its possible to do Sybilattacks, one trusted link to a 
"Sybil" is enough... however this leads to Network parts not very good connected
 to the rest. This leads to some ideas to prevent this. 

I also will try to provide some ideas about the semi-opennet if possible, since 
you know I am advocating it. However for me the theoretical aspects and the 
practical usablity might differ :)

Ideas can be Peer Introduction, Topological characteristica, geometrical 
characterisca of the network.

If there is alreay work done on this matter for freenet, I would be very glad to
see it. The thesis will be written till September, and I'll publicate it (if 
possible) and inform you about the results. However: the thisis will be 
theoratical, I already have some Ideas which won't be that practical, however I 
hope I can give a piece to this projects puzzles.

I hope I won't run in a dead end, and the final answer shouldn't be: "its 
entierly impossible."

I am very open to thoughts and Ideas.

Greets
Thomas Bruderer