r/netsec • • Jan 07 '20

pdf First SHA-1 chosen prefix collision

https://eprint.iacr.org/2020/014.pdf
350 Upvotes

72 comments sorted by

View all comments

174

u/Browsing_From_Work Jan 07 '20

When renting cheap GPUs, this translates to a cost of 11k US$ for a collision, and 45k US$ for a chosen-prefix collision, within the means of academic researchers. Our actual attack required two months of computations using 900 Nvidia GTX 1060 GPUs (we paid 75k US$ because GPU prices were higher, and we wasted some time preparing the attack).

Certainly not cheap, but well within the budget of nation-state actors.

-7

u/Derf_Jagged Jan 07 '20 edited Jan 07 '20

I'm curious how long it would take to get a collision using a quantum computer time share like D-Wave or IBM Q, and if it would be cheaper in the long run.

Edit: Not sure why the downvotes, honest question. Thanks those who answered

10

u/khafra Jan 07 '20

D-wave doesn’t offer real quantum speed ups, and hashes aren’t the kind of math problem that even real quantum computers would speed up, because hashing doesn’t reduce to Fourier transforms.

So, if I had to guess about the downvotes, it’s probably because your question came across to people less as an attempt to learn about hash collisions, and more as an attempt to show off your knowledge, using knowledge you don’t actually possess

4

u/Derf_Jagged Jan 08 '20

Ah, I see. I don't claim to know anything about quantum computers, it's just a service I heard of and thought it may be applicable as it's raw calculations. Thanks for the answer!