Re: V3 secret keys

Ben Laurie <ben@algroup.co.uk> Thu, 02 February 2006 17:55 UTC

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Message-ID: <43E23D08.10806@algroup.co.uk>
Date: Thu, 02 Feb 2006 17:10:32 +0000
From: Ben Laurie <ben@algroup.co.uk>
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To: "Daniel A. Nagy" <nagydani@epointsystem.org>
CC: OpenPGP <ietf-openpgp@imc.org>
Subject: Re: V3 secret keys
References: <43E20DB6.30209@algroup.co.uk> <20060202140612.GA13906@epointsystem.org>
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Daniel A. Nagy wrote:
> On Thu, Feb 02, 2006 at 01:48:38PM +0000, Ben Laurie wrote:
>> in 5.5.3 it says:
>>
>> "Furthermore, the CFB state is resynchronized at the beginning of each
>> new MPI value,  so that the CFB block boundary is aligned with the start
>> of the MPI data."
>>
>> I can't find anywhere a precise (or even an imprecise) definition of
>> "resynchronized". What exactly does it mean?
>>
>> Does it mean that the IV is reset to whatever it was at the start of the
>> current block? Does it mean that we use the partially-updated IV, but
>> set the position back to the beginning? Does it mean we reset the IV to
>> the initial value and start again? Or what?
>>
>> Cheers,
>>
>> Ben.
> 
> It means the usual CFB synchronization with outputting a partial block and
> shifting the IV.

If that means anything at all, you appear to be describing standard CFB
when applied to a partial block, which I assume the above is not.

-- 
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