Subject: [ietf-tls] RE: SHA algorithms -- WG Last Call for "AES Ciphersuites for TLS"

From: "John Banes" <[email-masked]>
Date: Fri, 8 Jun 2001 14:11:00 -0700

Pete, have you looked at the new SHA algorithms that are being defined
over at NIST? These algorithms have a much larger digest size that SHA-1
and are intended to provide security consistent with the longer key
sizes provided by AES.

I think that you should consider specifying that the SHA-256 or SHA-512
algorithms be used in the new AES cipher suites, particularly the ones
using 256-bit AES. 

Here are a couple of links to the new SHA algorithms:

http://csrc.nist.gov/encryption/tkhash.html
 
http://csrc.nist.gov/encryption/shs/dfips-180-2.pdf

Regards, 

John Banes

-----Original Message-----
From: Win Treese [mailto:[email-masked]]
Sent: Wednesday, May 30, 2001 6:36 AM
To: IETF Transport Layer Security WG
Subject: [ietf-tls] WG Last Call for "AES Ciphersuites for TLS"

This is LAST CALL for comments on advancing the draft "AES
Ciphersuites for TLS" to Proposed Standard. The last call period is
two weeks for the working group. 

The current draft is draft-ietf-tls-ciphersuite-03.txt and is at
http://www.ietf.org/internet-drafts/draft-ietf-tls-ciphersuite-03.txt
ftp://www.ietf.org/internet-drafts/draft-ietf-tls-ciphersuite-03.txt

Win Treese
Chair, TLS working group
[email-masked]

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From: Pete Chown <[email-masked]>
Date: Mon, 11 Jun 2001 13:44:39 +0100

> algorithms be used in the new AES cipher suites, particularly the ones

Don't forget that when SHA-1 is used in HMAC, it delivers 160 bits of
strength, as far as we know.  SHA-1 is looking a bit weak when it is
used as an (unkeyed) hash function because it only has 80 bits of
resistance to a birthday attack.

-- 
Pete

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