Re: message digest of large files

From: Kristian Gjøsteen (
Date: 08/18/05

Date: Thu, 18 Aug 2005 07:24:34 +0000 (UTC)

James Whitwell <> wrote:
>Is there a way of determining what the chances of two hashes for
>different files being the same are?
>The files are PDFs that have
>been encrypted using Blowfish, so I'd assume they're pretty random.

If the files are properly encrypted, they will look random.

While SHA-1 has been broken, it is quite unlikely to give collisions
for any set of random files you give it. If this happened with any
significant probability, it would probably have been noticed by

(On the other hand, if the data you are hashing is not under your
control, all bets are off.)

Kristian Gjøsteen