Post #1253033

2026-03-25 21:34 UTC

@dangoodin @esoteric_programmer yeah, the SHA1 breakage happened with good old transistor based classical computers: https://csrc.nist.gov/news/2017/research-results-on-sha-1-collisions Quantum attacks on hash functions exist, but are not considered feasible in practice, similar to attacks on other symmetric cryptography, the quantum advantage is very small in this case, just an asymptotically polynomial speedup, that is not believed to be an actual speedup for the sizes in use. This differs from asymmetric cryptography (RSA and elliptic curves), where quantum computers have an exponential advantage over the best known classical algorithms.

Replies (1)

@esoteric_programmer@social.stealthy.club 2026-03-26 10:32

@sophieschmieg @dangoodin ah, interesting! I seem to remember someone saying that quantum computers managed to break sha1 already, spreading FUD about regular encryption and how close we are to everyone's encryption being broken, even though this was already done previously with regular computers. I can't find that article anymore indeed, but the one linked above is the one I was thinking of about doing this with normal computers. I'm trying to read the paper linked to in the article at the top of this thread, but the formatting is a bit weird, at least when reading it with the Firefox PDF viewer, and also the mathematical proofs are rendered with Unicode symbols instead of something that would translate to math ML, making it harder for the screenreader to access it, but I'm getting to understand the basics at least. Thing is, a lot of hype about quantum computers, and FUD about regular ones being obsolete in many instances already, were spreading in the past, same about blockchain and so on, that it's hard to take this stuff seriously anymore, so it's good that more papers from the people actually working with this stuff are being published.

Open ##1253034