On Wed, Jun 07, 2023 at 07:25:48AM -0500, Orie Steele wrote: > > HPKE should work without creating new key types for dh kems, and > should work with existing APIs that currently generate keys and > envelopes based on alg.
The first part works, and I have written an implementation. The second part has _never_ worked in either JOSE nor COSE. I believe the current record is 5 different key subtypes for one alg (for both COSE and JOSE)! > A single equality check should confirm if the suite is acceptable to > the recipient, if they have a restricted key. And what about check if suite is acceptable for _sender_? I think that barring a major flaw in HPKE, there is no need for recipient to ever have a restricted key. Interop is separate matter, and there can be many different supported combinations. > The size and expression of the alg value, should be debated, but > following the conventions and fully specifying HPKE with alg, should > be resolved first. The convetion in COSE is to _not_ have ciphersuites. The some stuff that looks a bit like ciphersuites is just size optimizations. > COSE HPKE will need to update registries, so let's make the minimal > updates necessary to support what the industries wants to use. I think the minimum number of registry changes possible is 3. - A new alg - A new header parameter - A new key type or a reserved crv range. > We don't need to create new key types. It is much cleaner to create a new key type than to reserve a crv range. How is HPKE KEM 48 represented in _systematic_ manner? > We don't need to expose a new way to parameterize alg. Doing so saves a lot of work. > If we don't know which alg values for COSE HPKE need to be registered, > we can wait till people show up who do. What we do know is that it is either going to be a long list among time or 1 up-front. > A simple RFC that follows conventions doesn't take long to update the > registry. It is still unnecressary work. -Ilari _______________________________________________ COSE mailing list [email protected] https://www.ietf.org/mailman/listinfo/cose
