[openpgp] Re: I-D Action: draft-ietf-openpgp-replacementkey-01.txt

[Andrew Gallagher <[e-mail]>]

Hi, all.

> On 22 Oct 2024, at 15:08, Andrew Gallagher <[e-mail]> wrote:
> 
> As I see it, there are three broad options (in order of preference) [1]:
> 
> 1. Both fingerprint and imprint are required (no change)
> 2. Imprint is optional, either:
> 	a. iff it is the same as the fingerprint
> 	b. at the key owner’s discretion
> 3. Fingerprint is optional, either:
> 	a. iff it is the same as the imprint
> 	b. at the key owner’s discretion
> 
> The “opportunistic truncation” options 2a and 3a are effectively the same, just with the fields reordered on the wire. They complicate the parser in exchange for saving some bytes on the wire, but otherwise have the same functional and security properties as option 1.
> 
> If we choose option 2b, we have to accept that (1) the imprint is not necessary for key equivalence, or (2) key equivalence is not always achieved even with matching forwards and reverse subpackets.
> 
> If we choose the “aggressive truncation" option 3b, or wish to keep it open for some later date, we need to reorder the fields so that the fingerprint comes at the end of the record, and we will have to accept that fingerprint search may no longer be possible, which is a significant breaking change in the ecosystem.

I’ve seen no further discussion of this on the list or elsewhere. If there is no strong consensus in favour of any of the other options, the default will be to stick with option 1, i.e. no change to the current draft.

A