Re: Authenticated cipher modes

[Derek Fawcus <dfawcus%cisco.com@localhost>]

On Mon, Apr 18, 2005 at 10:48:21AM +0200, Henrick Hellström wrote:
> While trying to figure out how to support CCM, EAX and OCB cipher modes 
> or the Helix cipher (http://www.schneier.com/paper-helix.pdf), I spotted 
> an issue with SSH-TRANS. These cipher modes have built in data 
> integrity, but the SSH-TRANS algorithm negotiation mechanism clearly 
> isn't designed to handle such encryption.


> Selecting CCM mode and the "none" data integrity algorithm would 
> result in the desired state.)

I've not read Helix.  However in general I'd assumed that use of a encryption
including integrity algorithm could always simply be used with SSH by choosing
a SSH MAC of "none".  Certainly that's what I thought when I was considering
hacking in use of OCB.

DF