Re: [openpgp] AEAD Chunk Size

Derek Atkins <derek@ihtfp.com> Wed, 13 March 2019 13:14 UTC

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From: Derek Atkins <derek@ihtfp.com>
To: Vincent Breitmoser <look@my.amazin.horse>
Cc: Werner Koch <wk@gnupg.org>, openpgp@ietf.org
References: <87d0n174w6.fsf@wheatstone.g10code.de> <87mumh33nc.wl-neal@walfield.org> <3GFS71V7BTJNZ.29C5TO8OY0O44@my.amazin.horse>
Date: Wed, 13 Mar 2019 09:14:37 -0400
In-Reply-To: <3GFS71V7BTJNZ.29C5TO8OY0O44@my.amazin.horse> (Vincent Breitmoser's message of "Mon, 11 Mar 2019 12:43:49 +0100")
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Subject: Re: [openpgp] AEAD Chunk Size
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Vincent Breitmoser <look@my.amazin.horse> writes:

>> The chunking was introduced for just one purpose: To be able to detect rare
>> transmission errors earlier than at the end of the message.
>
> ...really? All this is just to save a few cpu cycles in the rare cases of data
> corruption that should have been handled by other layers (filesystem / transport
> layer) in the first place? Why even bother?

No, it is more than that.  Imagine using OpenPGP to encrypt a full
filesystem to tape backup.  You necessarily want to be able to chunk
that as you are saving (and restoring).

-derek
-- 
       Derek Atkins                 617-623-3745
       derek@ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant