<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">On 13 Sep 2025, at 07:25, Jacob Bachmeyer via Gnupg-devel <gnupg-devel@gnupg.org> wrote:<br><div dir="ltr"><blockquote type="cite"><br></blockquote></div><blockquote type="cite"><div dir="ltr">Do I correctly gather that LibrePGP defines v5 and RFC9580 defines v6?</div></blockquote><div><br></div><div>Partly, yes. LibrePGP defines version 5 keys and signatures, type 20 aead/ocb encrypted data, and various other minor changes. RFC9580 defines version 6 keys and signatures, SEIPD2 encrypted data, and other changes - some of which correspond to librepgp and some of which do not. “v5” and “v6” are often used as shorthand, but they do not capture the whole picture. Daniel’s summary at <a href="https://mailarchive.ietf.org/arch/msg/openpgp/aqBy97lj2P4DVxTds0eKZDVdmms/">https://mailarchive.ietf.org/arch/msg/openpgp/aqBy97lj2P4DVxTds0eKZDVdmms/</a> is technical, but comprehensive. </div><br><blockquote type="cite"><div dir="ltr">If so, where is the problem? What prevents both of those from co-existing and implementations eventually supporting both?</div></blockquote><br><div>Technically, there is no fundamental issue - several library implementations currently support both, to various extents. The real trick is how to present (or avoid presenting) these changes to the user. Choreographing a version bump is tricky enough at the best of times —organising two competing ones sumultaneously has taxed the minds of many people in the *pgp space to destruction and back.</div><div><br></div><div>As Kai pointed out in another reply, there are mechanisms (both current and potential) available to help ease a transition, but these all depend on the various implementations playing nice with each other. If one major implementation does not wish to cooperate, users of all implementations will inevitably stumble over interoperability issues at some point, and mitigating the resulting pain is very difficult, and probably impossible, through unilateral action.</div><div><br></div><div>A</div></body></html>