Re: [openpgp] To bind or not to bind

[Aron Wussler <[e-mail]>]

Hi all,

Thanks for keeping the discussion active.

> (1) Whether PQC encryption algorithms can be used only in v6 keys.

In general with no hat on, I would prefer to allow v4 PQC encryption. I am fine with a SHOULD NOT generate v4 PQC keys, in case this can be helpful to get to a compromise.

On the other hand, I think putting a MUST also means refusing V4 keys on the parsing end. I don't see any security disadvantage in making a v4 PQC key, and if this is a mere policy decision, then I would prefer a more liberal policy.

> (2) Whether PQC encryption algorithms can be used only with SEIPDv2

For me this is a hard no. As a user I'm gonna send that email anyway, and don't want to be bothered with splitting it up by recipient because of policy.

Cheers,
Aron


--
Aron Wussler
Sent with ProtonMail, OpenPGP key 0x7E6761563EFE3930



On Thursday, 21 March 2024 at 21:26, Aron Wussler <[e-mail]> wrote:

> Hello list,
> 

> Here's the follow-up on the dilemma we had at the IETF 119 session, whether PQC encryption should be bound to V6 or allowed with V4.
> 

> Note that this translates into two different issues:
> 

> (1) Whether PQC encryption algorithms can be used only in v6 keys
> (2) Whether PQC encryption algorithms can be used only with SEIPDv2
> 

> Note that (2) implies (1).
> 

> Please provide feedback on your preferences, use-cases, and motivations!
> 

> At the session the following arguments were already raised:
> - (1) may be justified because some implementations fail parsing keys [1]. Of this plot is particularly relevant the 3rd line (Unknown algo, opaque encoding, small), that would be equivalent to attach an ML-KEM + X25519 subkey to an existing v4 certificate. All V6 implementations are required not to choke on unknown algorithms.
> - TLS disallowed PQC in version 1.2 to promote the migration to 1.3
> - (2) implies a new failure mode for OpenPGP, where a message can not be sent to two different recipients having a v4 and a PQC key.
> 

> Cheers,
> Aron
> 

> 

> [1] https://tests.sequoia-pgp.org/#Mock_PQ_subkey
> 

> 

> --
> Aron Wussler
> Sent with ProtonMail, OpenPGP key 0x7E6761563EFE3930
>