Optional 'test' or benchmark cipher

Ben Lindstrom mouring at eviladmin.org
Thu Jan 17 05:09:11 EST 2008

On Wed, 16 Jan 2008, Chris Rapier wrote:

> Linda Walsh wrote:
>> I hope this is the right list, as I'm desiring a feature addition
>> in openssh.  I would like the option to have a 'null' cipher (after
>> the initial authorization, similar to 'delayed' for compression).
>> It would have to be enabled on both client and server and server
>> would never use it unless it was both enabled and asked for by
>> the client.
> You should look at HPN-SSH at http://www.psc.edu/networking/projects/hpn-ssh
> This implements the NONE cipher exactly as you describe with the caveat
> that it still generate HMACs. Authentication is fully encrypted and it
> then it switches to the NONE cipher. One important caveat is that you
> *cannot* use this NONE cipher in interactive sessions. Its only
> available for bulk data transfers.

Hmm.. I believe Markus established a few years ago that the HMAC is more 
costly in terms of preformance than most of the ciphers.

If one skims back through the list I think he gave preformance numbers 
which resulted in our default HMAC/Cipher combination (could be I also saw 
them via a different list.  That was too long ago) .. And I suspect 
that would have been around the late 2.x release to the early 3.x 

  - Ben

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