2 ms·
How did you validate it exactly? The first thing would be to validate the sha256 implementation used I guess. If it's true it's huge but I find it hard to trust
by simias 9y ago
How did you validate it exactly? The first thing would be to validate the sha256 implementation used I guess. If it's true it's huge but I find it hard to trust a random github repo with such an extraordinary claim, especially the very vague "I developed an entirely new type of cryptanalysis theory to achieve this. It has a similar form comparing to differential analysis." Raises many red flags as far as I'm concerned.
Even if it's true I'm not sure I understand how broad this attack vector could be. Can we generate collisions for any given hash or just a subset?
Given that SHA256 is used in cryptocurrencies it makes me even more skeptical, it could be an attempt at making the market crash with some FUD I guess.
- andreser-mit 9y agoThe sha256.py in the attack repo matches https://github.com/thomdixon/pysha2/blob/master/sha2/sha256.py https://github.com/thomdixon/pysha2/blob/master/sha2/sha256..... up to whitespace. I have not sure that it matches the NIST spec, but it matches wikipedia on emptystring...
- lisper 9y ago> How did you validate it exactly? I ran the example. Then I looked at the code. Then I ran random test vectors against hashlib.sha256. It's not a slam-dunk, but if it's a hoax it's a damn good hoax.
- dsacco 9y agoIt's not a good hoax at all. You can calculate fixed points for SHA256. This is a quirk, but it's not less costly than actually finding a collision, which means this is a non-vulnerability. The author effectively hard-coded values.
- lisper 9y ago> You can calculate fixed points for SHA256 Really? How? [UPDATE] Heh, you're right. https://crypto.stackexchange.com/questions/48580/fixed-point-of-the-sha-256-compression-function https://crypto.stackexchange.com/questions/48580/fixed-point...