Re: Keyed-MD5, ITAR, and HTTP-NG

[Simon Spero <ses@tipper.oit.unc.edu>]

On Mon, 30 Oct 1995 hallam@w3.org wrote:

> 	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

What I've heard is that there are some worries about using short 
constants with MD5; maybe you could fill us in on the naughty stuff 
(someone said there were a load of papers in Crypto '95 on the subject?)

> 
> 	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.

Hey, you got a web-site? :-)

Simon

----
(defun modexpt (x y n)  "computes (x^y) mod n"
  (cond ((= y 0) 1) 	((= y 1) (mod x n))
	((evenp y) (mod (expt (modexpt x (/ y 2) n) 2) n))
	(t (mod (* x (modexpt x (1- y) n)) n))))