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Re: [openpgp] AEAD Chunk Size

Peter Gutmann <pgut001@cs.auckland.ac.nz> Fri, 29 March 2019 03:06 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: Jon Callas <joncallas=40icloud.com@dmarc.ietf.org>, Justus Winter <justuswinter@gmail.com>
CC: "openpgp@ietf.org" <openpgp@ietf.org>, Jon Callas <joncallas@icloud.com>
Thread-Topic: [openpgp] AEAD Chunk Size
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Date: Fri, 29 Mar 2019 03:06:15 +0000
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Subject: Re: [openpgp] AEAD Chunk Size
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Jon Callas <joncallas=40icloud.com@dmarc.ietf.org> writes:

>Okay, prior to this working group, when there was running code without a
>consensus rough or not, this problem existed. Even with compression, PGP 2
>ran on DOS machines with a max of 640K of RAM.

The constraint there was 64K, not 640K, the x86 segment size.  Also, the way
PGP then handled it was to use intermediate files for everything, every single
transformation wrote its own intermediate file to disk.  Including, in the
worst case, prepending a single literal byte to the data.

That's probably not a good example to cite :-).

Peter.

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