Keyed-MD5, ITAR, and HTTP-NG

[hallam at w3.org]

Simon,

	Do not spec Keyed MD5, it is a complete looser. It is actually weak
against a number of attacks. There are much better constructs for creating
a keyed digest. There are much better ways of creating a digest than using
a hash fuinction as the base.

	There is some work by Phil Rogaway on making keyed digest functions
which I strongly recommend people look at. I can post a paper on the subject if 
people are interested.

		Phill