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Proof-of-work is bad rate limiting: https://news.ycombinator.com/item?id=44093918 https://news.ycombinator.com/item?id=44093918. The playing field is wildly unb
by chrismorgan 4mo ago
Proof-of-work is bad rate limiting: https://news.ycombinator.com/item?id=44093918 https://news.ycombinator.com/item?id=44093918. The playing field is wildly unbalanced. Even naive attackers tend to have a lot more computing power available than a lot of your normal users, and where it’s SHA-256 (which is almost the worst choice imaginable for a proof of work scheme, yet which every single service that I know of has used), an intelligent attacker goes from being hundreds of times as powerful to millions of times as powerful.
- netik 4mo agoI agree with this assessment but for many applications it's a viable approach, until the attacker goes off and writes their own shader to solve the PoW. We go to back to threat modeling here, and looking at the amount of effort vs gain here. They're now integrating Argon2ID in an attempt to squash GPU hacks but it places ridiculous demands on the client being Memory hard.
- ameliaquining 4mo agoThis seems like the real mechanism here is not actually proof-of-work so much as security-through-obscurity.
- CodesInChaos 4mo agoDid they evaluate good old bcrypt? I haven't looked at it in a while, but it used to be very GPU unfriendly (though still vulnerable to FPGA/ASIC).