Ask HN: How long until quantum computers break 512 bit RSA/ECDSA? 1024 bit?

13 points·actinium226··22 comments

The more detailed your answer the better!

I'm pretty sure RSA 512 was broken a long time ago: https://arstechnica.com/information-technology/2015/10/break...

Oh wow, didn't realize 512 can already be factored. Thanks for this.

RSA-1024 is also a rather aggressive / dangerous choice, even before a quantum computer arrives: NIST SP 800-131A rev2 Table 2 and 5 forbid use of anything below 2048-bit RSA. Academic teams have actually broken up to RSA-829: https://en.m.wikipedia.org/wiki/RSA_Factoring_Challenge

Don’t roll your own crypto - just select a TLS cipher suite using Mozilla’s recommendations - but for hobby purposes, prefer Curve25519 or NIST P-256. Or play around with Kyber, post-quantum crypto is neat.

AFAIK quantum computers currently can only handle a dozen qubits or less. So we can't really extrapolate about timeframes yet, there's not enough data points to draw a curve. It could happen this year, it could never happen.

Careful with the terminology there. They do not “handle” the states but rather “access” or “read” them: moreover the qubits read are not processed along any probability vector which means they are scraping inherently junk data.

By analogy: imagine you want to make an aimbot to shoot people in an online FPS video game. You need your aimbot to calculate not only the vector to shoot at (our game has bullet drop and bullet objects, not hitscan weapons) but also to calculate for the opponent’s motion.

The way people at Google are doing it now, they look at a map of where the players are where when the game starts and try to ammo dump it… with no one there. Lol.

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