History hash collisions

[Russ Allbery]

Fabien Tassin <fta at oleane.net> writes:

> several months ago, Matt (Dillon) made a similar work with its CRC-16 to
> CRC-64 hash code for Diablo.

> Read http://www.backplane.com/diablo/crc64.html for the details..

This is a very interesting page; this indicates that good 48-bit hash
(which is what we have now) should be fine, but that a 64-bit hash should
be well out of the range of trouble.  Admittedly, larger is better as
Usenet grows, and 128-bit would be nice.

I wonder about how easy it would be to attack CRC-64, though.  Hm.  I'd
sleep better with a cryptographically strong hash like we're using than
with something like he's using.

-- 
Russ Allbery (rra at stanford.edu)         <URL:http://www.eyrie.org/~eagle/>