Subject: Re: some comments on ikev2 04

From: "Andrew Krywaniuk" <[email-masked]>
Date: Sat, 01 Feb 2003 15:53:46 -0500

>
>(7) Security considerations:
>
>- can you explain to me what is the meaning of the first paragraph.
>In what sense is the entropy of the DH consumed? (what is this entropy
>anyway?) Maybe you want to say that using the same phase 1 with many
>non-DH phase 2's compromises the PFS property of the protocol.

I always hated that text as well, as it doesn't make any sense. About a year 
ago, I proposed the following alternate text:

"Repeated re-keying using Phase 2 without PFS will increase the
amount of data that will be exposed if the Diffie-Hellman key is ever
compromised. Rekeying without PFS could also aid an attacker in
cryptanalysing encrypted ESP data if a weakness in the PRF algorithm is ever 
discovered."

Andrew
--------------------------------------
The odd thing about fairness is when
we strive so hard to be equitable
that we forget to be correct.

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