comments on draft-ietf-ipsec-ciph-cbc-02.txt

Markku-Juhani Saarinen <mjos@ssh.fi> Thu, 12 March 1998 15:49 UTC

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Date: Thu, 12 Mar 1998 18:02:29 +0200
From: Markku-Juhani Saarinen <mjos@ssh.fi>
To: ipsec@tis.com
Subject: comments on draft-ietf-ipsec-ciph-cbc-02.txt
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The draft does not mention that the RC5 encryption algorithm is patented
(pat.no. 5,724,428).

We feel that a 4-round variant of IDEA can not provide the level of
security that it's key length would suggest. Cryptoanalytic attacks on 
3 and 3.5 - round variants of IDEA has been published. 

The weak key lists are incomplete, as they will probably always be.
The chances of hitting one at random is negligible. What's the point ?

- mj

Markku-Juhani O. Saarinen <mjos@ssh.fi>, SSH Communications Security Ltd