ISI, R.C. ATHENA ISI, R.C. ATHENA ISI, R.C. ATHENA ISI, R.C. ATHENA This document specifies extensions to the Ephemeral Diffie-Hellman Over COSE (EDHOC) protocol to provide resistance against quantum computer adversaries by incorporating Post-Quantum Cryptography (PQC) Key Encapsulation Mechanisms (KEMs) for both key exchange and authentication. It defines a new signature-free KEM-based authentication method in which both parties authenticate using KEMs, enabling quantum-resistant authentication without relying on digital signatures when PQC KEMs, such as the NIST-standardized ML-KEM, are used.