Re: [Cfrg] Point format endian

Actually, AFAIK, *every* IETF-developed Internet protocol (not just in Security area) uses Big Endian for on-the-wire.

--
Regards,
Uri Blumenthal                            Voice: (781) 981-1638
Cyber Systems and Technology   Fax:   (781) 981-0186
MIT Lincoln Laboratory                Cell:  (339) 223-5363
244 Wood Street, Lexington, MA 02420-9185       

Web:  http://www.ll.mit.edu/CST/
MIT LL Root CA:  <https://www.ll.mit.edu/labcertificateauthority.html>

----- Original Message -----
From: Derek Atkins [mailto:derek@ihtfp.com]
Sent: Tuesday, January 27, 2015 10:41 AM
To: Stephen Farrell <stephen.farrell@cs.tcd.ie>
Cc: 'cfrg@irtf.org' <cfrg@irtf.org>; Peter Gutmann <pgut001@cs.auckland.ac.nz>
Subject: Re: [Cfrg] Point format endian

Stephen Farrell <stephen.farrell@cs.tcd.ie> writes:

> On 27/01/15 10:34, Peter Gutmann wrote:
>> The universal standard for crypto bignums is big-endian
>
> Hmmm.... sez who? :-)

PKIX, OpenPGP, OpenSSH, Kerberos, TLS...  Pretty much every existing
IETF security standard I know of to date encodes numbers in big-endian
format.

> But seriously, if in fact this makes little or no difference,
> which I believe is the case, and which I believe you are also
> arguing, then what is the problem with going with the initial
> coder's choice here?
>
> If there is no problem then just doing that and making sure
> it's properly documented should be just fine I'd have thought.

It would mean a completely separate code path to support 25519 versus
supporting most (all?) existing ECC curves.

> S.

-derek
-- 
       Derek Atkins                 617-623-3745
       derek@ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant

_______________________________________________
Cfrg mailing list
Cfrg@irtf.org
http://www.irtf.org/mailman/listinfo/cfrg