Re: [TLS] Consensus for AEAD IV

Martin Thomson <martin.thomson@gmail.com> Fri, 24 April 2015 20:00 UTC

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Date: Fri, 24 Apr 2015 13:00:50 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Joseph Salowey <joe@salowey.net>
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Subject: Re: [TLS] Consensus for AEAD IV
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On 24 April 2015 at 10:10, Joseph Salowey <joe@salowey.net> wrote:
> The general consensus on the list seems to prefer to derive "IV" and use it
> to make the AEAD nonce less predictable. Most folks seemed to be OK with
> this approach.    In Dallas, there was significant support for using the
> derived "IV" as a per session XOR mask for the counter.  If you have
> objections to this approach please respond on the list by May 1, 2015 .


You aren't being particularly precise about the process here.

I believe that these were the two options that were most debated:

a)  nonce = zeroes(N_MIN) XOR counter
b)  nonce = HKDF(...., N_MIN) XOR counter

Did you mean the latter option?