"William" == William H Geiger <whgiii(_at_)openpgp(_dot_)net> writes:
William> Actually MD5 seems too large for this but I don't know a
William> good replacement that would be smaller than MD5 but still
William> large enough to be collision resistant.
Too large in what sense? If you want shorter, just truncate it.
That's what IPSEC does. If you want faster, how collision resistant
does it have to be? If you don't need a secure hash, how about CRC?
There's CRC-32 of course, nice and fast. If you need longer, there's
CRC-64, don't know a good polynomial for that but I know there is one.
paul