Re: [9fans] SHA-1 collision and venti

[erik quanstrom <quanstro@quanstro.net>]

On Mon Feb 27 14:17:49 PST 2017, charles.forsyth@gmail.com wrote:

> I think venti could deal with it: Rwrite returns a score, Tread provides a
> score, and the caller typically uses it as an opaque value. If not, whether
> a different sha1 is returned or a new algorithm is used, the caller could
> still not rely on sha1(block)=score.
>
> In any case, fossil needs a fix to cope with venti returning "score
> collision", to prevent it failing to archive once it hits a shattered file,
> or rather the first venti-sized block of them.

i believe that rsc worked this out in some work he did based on venti.
sadly i don't remember the name of the project.

a modest proposal.  since p(collison) is calculated for a random collison,
why not just store encrypted blocks.

- erik