Git and the new SHA-1 prefix collision attack
- Date: Wed, 15 May 2019 14:22:28 +0200
- From: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
- Subject: Git and the new SHA-1 prefix collision attack
[CC-list carried forward from the last SHA-1 thread I found]
Thought I'd sent a brief line about this since nobody else did.
There's a newly published "From Collisions to Chosen-Prefix Collisions
Application to Full SHA-1" paper making the news this week which builds
on the SHAttered attack: https://eprint.iacr.org/2019/459.pdf
See https://shattered.io for that original attack.
I asked Marc Stevens on Twitter whether the sha1collisiondetection
library would cover the sorts of collisions generated by the method
described in this paper. He said yes:
Not all the details are out on this new attack, in particular the
researchers (CC'd) haven't yet published details on improvements that
would make such an attack cheaper to carry out than the current
state-of-the art, which I understand from Marc's Twitter feed is
something he's skeptical about.
In any case, it looks like the sha1collisiondetection library will save
the day again. Thanks Marc & Dan!