Subject: [COSE] [cose-issues] Make “recipients” field optional (#10)

From: Mike Jones <[email-masked]>
Date: Sun, 1 Nov 2015 10:39:47 +0000

This was a size optimization and simplification proposed in the presentation “ACE/CORE requirements on COSE” https://www.ietf.org/proceedings/93/slides/slides-93-cose-6.pdf on slide 7, and illustrated by additional slides. I’ll note that draft -06 is already part way down this road by defining a Direct Encryption mode in Section 12.1. Also define Direct Signature and Direct HMAC data structures in which no “recipients” field is present, and that will go a long way towards making the simple cases simpler (and smaller).

Note that this is issue is related to the “Allow single wrapping for symmetric key encryption + signature” requirement from ACE/CORE on the same slide and the “include a key management structure only when needed” issue on slide 6 of the “COSE Key Issues And Choices” presentation at https://www.ietf.org/proceedings/93/slides/slides-93-cose-7.pdf.
View it on GitHub at https://github.com/cose-wg/cose-issues/issues/10