August Cellars The CBOR Object Signing and Encryption (COSE) syntax [I-D.ietf-cose-rfc8152bis-struct] does not define any direct methods for using hash algorithms. There are however circumstances where hash algorithms are used: Indirect signatures where the hash of one or more contents are signed. X.509 certificate or other object identification by the use of a thumbprint. This document defines a set of hash algorithms that are identified by COSE Algorithm Identifiers.