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

>At the moment, I'm thinking of making the mandatory schemes be Keyed MD5
>for authentication, and weakened RC4 with an IV for confidentiality, with
>the added stipulation being that the user must be informed when key
>weakening is being used. I may swap RC4 for DES; they're both public 
>domain, but RC4 is simpler. They're both shared key, but I don't make PK 
>stuff mandatory. 

The licensed version of RC4, or the software that was posted anonymously?

Do you really feel comfortable basing an IETF standard on that?  When
you use the term RC4 do you mean the real version or the posted one,
what will you do if they ever conflict?  Can you even use the name RC4
for the posted version?  It seems to me that RC4 means the RSA licensed
code, which presumably you wanted to avoid when you wrote no mandatory PK.

Where would you swap RC4 for DES?

I assume your added stipulation is a "should" not a "must" item.

How are you going to handle key management and naming?
	/r$

On Mon, 30 Oct 1995, Rich Salz wrote:

> The licensed version of RC4, or the software that was posted anonymously?

Cop-out: That algorithm described in Applied Cryptography 2nd Edition 
under the label RC4.

> Where would you swap RC4 for DES?

The swap would take place in the list of schemes that must be supported 
by conforming applications. 

> I assume your added stipulation is a "should" not a "must" item.

Correct [strong should, but still should]

> How are you going to handle key management and naming?

The protocol's part of key management for OOB shared keys is taken care 
of by naming; session key exchange with PK is not yet fully defined, but 
will  look a lot like either SKIP or Photuris. 

Naming:
   Names are strings, of the format <domain>:<name>, where domain is the
name-space from which the names are taken. The following domains are
pre-defined: 

DN:	X.500 Distinguished name. The name portion contains the RFC1485 
	ascii encoding of the DN.

URN:	Uniform Resource Name. The name consists of a URN (whatever that 
	turns out to be).

PGP:	PGP format name. A PGP user name.


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))))