Hi Daisuke, With your proposal and Ilari’s proposal there are two ways to encode public keys in COSE libraries. This adds complexity. Complexity leads to security problems.
Here is my question to you: How do you deal with this added complexity? (FWIW this is not something you mention in your comparison table.) Ciao Hannes From: COSE <[email protected]> On Behalf Of AJITOMI Daisuke Sent: Friday, September 23, 2022 12:00 AM To: Mike Jones <[email protected]> Cc: [email protected] Subject: Re: [COSE] COSE HPKE Public Key Format Consensus Call Thanks for initiating the consensus call. > 3. Other (please describe in sufficient detail to enable its specification) +1 to my proposal described in my previous post[1]. I have made a chart comparing my proposal to the current draft. As described in the chart, there are some problems with the current draft that cannot be overlooked. I would be happy if you could use it as a reference for your vote. https://docs.google.com/presentation/d/1azfHu93NCm5M9KUbpbtRze7aitvpBAj9SxhpvHe877M In addition, Mr. Richard Barnes also pointed out on the JOSE WG mailing list that it is incorrect to use COSE_Key to represent encapsulated keys[2]. I have the same opinion. As I mentioned repeatedly, the encoding format of the recipient public key and the encapsulated key (ephemeral sender's public key) should be considered separately. The former should be able to be expressed with COSE_Key, but the latter should not. Best regards, Daisuke [1] https://mailarchive.ietf.org/arch/msg/cose/ZY5v7jJr4SxHGIbeA3dgLC6eZDg/ [2] https://mailarchive.ietf.org/arch/msg/jose/IKIR_XusfHD26ewqZSt5ad2WUc8/ 2022年9月23日(金) 2:09 Mike Jones <[email protected]<mailto:[email protected]>>: As discussed at IETF 114, the HPKE draft uses the COSE_Key public key representation. The authors described that Ilari Liusvaara had proposed using a different public key representation, which is detailed in Slide 2 of https://datatracker.ietf.org/meeting/114/materials/slides-114-cose-cose-hpke-00. As recorded in the minutes<https://datatracker.ietf.org/doc/minutes-114-cose/>, consensus during the meeting appeared to be in favor of continuing to use COSE_Key. This note initiates a consensus call by the chairs on the topic of what public key format the COSE HPKE specification will use. Working group members are requested to express their preferences within two weeks of this note (by Thursday, September 6th) for either: 1. Continuing to use COSE_Key 2. Using the different format proposed by Ilari Liusvaara 3. Other (please describe in sufficient detail to enable its specification) Thank you, -- Mike (for the COSE chairs) _______________________________________________ COSE mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/cose IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
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