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[openpgp] Re: Encryption subkey selection

Andrew Gallagher <andrewg@andrewg.com> Mon, 07 April 2025 07:36 UTC

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From: Andrew Gallagher <andrewg@andrewg.com>
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Date: Mon, 07 Apr 2025 08:36:03 +0100
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To: Falko Strenzke <falko.strenzke@mtg.de>
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CC: Justus Winter <justus@sequoia-pgp.org>, openpgp@ietf.org
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Subject: [openpgp] Re: Encryption subkey selection
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Hi, Falko.

On 7 Apr 2025, at 07:50, Falko Strenzke <falko.strenzke@mtg.de> wrote:
> 
> But I think we need to define a default rank that is assigned to a subkey in the case that at least one encryption subkey in the certificate carries the ESS. That would probably be "0".

This would be reasonable. Another option would be to treat such encryption subkeys as “do not automatically select”. This might seem to render the subkey unusable, but some clients allow the user to manually override the default subkey selection algorithm, in which case it could still be used. It’s worth noting that gnupg appears to now interpret the “reserved for adsk” key flag this way.

A

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