Hi John, There seems to be a widespread perception that a kid is an identity.
(See, for example, the weird discussion that developed in the thread starting with Archived-At: <https://mailarchive.ietf.org/arch/msg/scitt/qaq8Ll-sqv9GW7sUP3xz0SlaI40>.) We should have been more explicit that a kid is a hint for finding a key; whether that key has any relationship to an identity is outside the scope of COSE (of course, further header parameters such as the “iss” proposed in the above thread could help with finding the identity). >> I understood that a kid would map to multiple keys, but all of those keys >> would be owned by the same party. From what I understand, the attack >> described here only occurs when one kid maps to keys owned by distinct >> parties. >> Which is the correct interpretation? And should the second case actually be >> allowed? I didn’t read the LAKE thread yet, but there seems to be an intrusion of the thinking I alluded to above. > Whatever the answer is, it might be good to update > ietf-cose-rfc8152bis-struct with a sentence to clarify. I think the text in COSE is fine. People just don’t want to read what it says… Note that there is nothing about kid that would make you believe all matches for a kid are “owned by the same party”. That is not even terminology that COSE defines... It might be more useful to actually start a RFC 8725 equivalent that shows good ways to use COSE, instead of tinkering with the approved specification. Grüße, Carsten _______________________________________________ COSE mailing list [email protected] https://www.ietf.org/mailman/listinfo/cose
