Re: [Monotone-devel] Hash collisions resiliency

[Nathan Myers]

On Thu, Apr 14, 2005 at 08:10:21AM +1000, William Uther wrote:
>   I'm a little confused here.  People are saying that hash collisions 
> are hard to detect - that you'd have to do a full-text check of all the 
> files.  That doesn't seem right.  Couldn't you just have a table of 
> hashes in the database.  

No.  Suppose you add a file to your repository, and I add one to 
mine.  Unbeknownst to us, they has the same.  When we reconcile our
repositories, now there are two files with the same hash.

If you compared length, too, that would be equivalent to adding
more bits of hash.  Going to SHA-256 would be better than comparing
lengths.

Nathan Myers
address@hidden