Formal Verification of PKMv3 Protocol Using DT-Spin

WiMax (Worldwide Interoperability for Microwave Access, IEEE 802.16) is a standard-based wireless technology, which uses Privacy Key Management (PKM) protocol to provide authentication and key management. Three versions of PKM protocol have been released and the third version (PKMv3) strengthens the security by enhancing the message management. In this paper, a formal analysis of PKMv3 protocol is presented. Both the subscriber station (SS) and the base station (BS) are modeled as processes in our framework. Discrete time describes the lifetime of the Authorization Key (AK) and the Transmission Encryption Key (TEK), which are produced by BS. Moreover, the PKMv3 model is constructed through the discrete-time PROMELA (DT-PROMELA) language and the tool DT-Spin implements the PKMv3 model with lifetime. Finally, we simulate communications between SS and BS and some properties are verified, i.e. liveness, succession and message consistency, which are extracted from PKMv3 and specified using Linear Temporal Logic (LTL) formulae and assertions. Our model provides a basis for further verification of PKMv3 protocol with time characteristic.