CBOR Object Signing and Encryption
COSE defines how to sign, MAC, and encrypt data encoded in CBOR, a compact binary format suited to constrained devices. It is the binary counterpart to the JSON-based JOSE family and is specified in RFC 9052. COSE is widely deployed in WebAuthn and FIDO2 attestation, IoT security protocols, and digital credentials such as the EU Digital COVID Certificate and ISO mobile driving licenses.