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by ralala 3652 days ago
For most of the P2P overlays there are multiple serious attack possibilities (Sybil attack, routing table poisoning).

Some years ago in the university I wrote a paper about that in a seminar to summarize the possible counter meassures, but from what I remember, there were no really practical solutions. I think the most promising one is the use of a centralized certificate authority, which reintroduces some of the problems p2p wanted to solve. Does anyone know if new ideas have come up in the last years?
2 comments
pdimitar 3652 days ago
You should read about the implementation of IPFS and how it tackles this exact problem. Look it up, it's readily accessible from the first few results in Google.

I believe their system will work. Or require only minor tweaks.

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the8472 3652 days ago
http://doc.tm.uka.de/SKademlia_2007.pdf

Combine that with using the global overlay only for bootstrapping of common-interest sub-networks and you'll limit the incentives that an attacker will have to attack the global overlay while also reducing the effectiveness because a single non-fake contact will be sufficient to join the subnetwork.

It's not an absolute defense (sybil-resistance without central authority is hard) but in practice it won't be worth it for attackers.

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ralala 3650 days ago
I think it's still important to find a good balance for the computational cost of the crypto puzzle.

Attackers will probably have a lot of computational resources (think of AWS, botnets, GPU computations), while typical users don't (mobile phones).

I haven't had time yet to look into the IPFS details yet, but thanks for the reference.

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