Re: [openpgp] SHA3 algorithm ids.

Peter Gutmann <pgut001@cs.auckland.ac.nz> Wed, 19 August 2015 09:45 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: Andrey Jivsov <openpgp@brainhub.org>, "openpgp@ietf.org" <openpgp@ietf.org>
Thread-Topic: [openpgp] SHA3 algorithm ids.
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Date: Wed, 19 Aug 2015 09:45:31 +0000
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Subject: Re: [openpgp] SHA3 algorithm ids.
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Andrey Jivsov <openpgp@brainhub.org>; quoted Werner Koch:

> Note that I ordered SHA3-224 first; when we did SHA2 we forgot about 224
> and thus it ended up out of order.

And that's pretty much what the -224 hashes are, forgettable (and -384 only
slightly less so).  There's an obvious need for -256, and then you need -512
for people who need hashes that go to 11, but what's the point of -224 and
-384 in OpenPGP?  Are users really going to say "well, everyone else is using
-256 and I like to be different, but -512 is too big, and -384 just doesn't go
with the tie I'm wearing, so I'm really glad there's -224 as well"?  It's just
more bloat in the spec (and implementations) that'll never be used by anyone.
It was forgotten in 4880, it should be forgotten in x880 as well (along with
the equally useless -384).

Peter.