Pardon the cross-posting...

A pretty strange subject line, right? :)

However, there is a reality in the form of constrained devices that in order to 
use COSE must either turn to yucky infinite-length encoding 
(https://datatracker.ietf.org/doc/html/draft-ietf-rats-eat-11#section-8.3.1) or 
create the entire payload in RAM, here assuming that the exact size of the 
payload in bytes is not known in advance.

X.509 certificates (that were created in a time when virtually all devices were 
constrained) do not suffer from these problems due to their reliance on deterministic 
encoding, followed by a separate signature item.   A further advantage of the X.509 
approach compared to COSE/CWT, is that the claims are not stuffed in a blob requiring yet 
another layer of decoding.  However, compared to ASN.1, CBOR is much more 
"RAM-friendly" since it doesn't impose a byte-length over items enclosed in a 
map or array.  Concatenation is all you need!

I believe the time has come to seriously look into alternatives to COSE since it was 
"inspired" by JOSE.   CBOR <<>> JSON.

This GitHub issue elaborates a bit more on this topic: 
https://github.com/ietf-rats-wg/eat/issues/168

Thanx,
Anders

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