Re:Anglo-Italian company says it has cracked Bitcoin. People...
by tromp on Monday March 25, 2024 @12:43PM
(#39818484)
You can avoid all operations (actually, gates since we're talking ASIC circuits) of the last round that only affect the least significant bits (e.g. the last 176 bits if the threshold is 2^80).
Re:Anglo-Italian company says it has cracked Bitcoin. People...
by refulgentis on Monday March 25, 2024 @12:31PM
(#39818321)
Crypto-noob here: let's say they broke SHA-256. Even then, they'd need to know the hash in advance, which they don't, right? It's really hard for me to follow, I'm getting old :(
EDIT: Looks like no, they don't need to know the hash. Rasulek wrote a great overview here: https://news.ycombinator.com/item?id=39818305
I'm still confused about the leading zeros thing. I thought the article author was using a leaky abstraction. It sounds suspicious/notgood that you have a significant amount of info up front. But I'm just a noob free-associating.
... no? That's the point of the hash function, that you can't compute it without computing all of it. This statement is equivalent to breaking the hash function (very severely), which lots of thought has gone into.
Granted, if you do have a break for SHA-256, arguably one of the best ways to commercialize it would be to secretly mine Bitcoin much faster than others.