Reusing Static Keys in Key Agreement Protocols

Abstract. Contrary to conventional cryptographic wisdom, the NIST SP 800-56A standard explicitly allows the use of a static key pair in more than one of the key establishment protocols described in the standard. In this paper, we give examples of key establishment protocols that are individually secure, but which are insecure when static key pairs are reused in two of the protocols. We also propose an enhancement of the extended Canetti-Krawczyk security model and definition for the situation where static public keys are reused in two or more key agreement protocols.

• Type: Conference
• Year: 2009
• Where: INDOCRYPT
• Authors: Sanjit Chatterjee, Alfred Menezes, Berkant Ustaoglu
• Keywords: Cryptology, INDOCRYPT 2009, Key Agreement Protocols, Key Establishment Protocols, Static Key Pairs