Cryptanalysis of NAKE Protocol Based on ECC for SIP and Its Improvement

In 2008, Wu et al. proposed a new authentication and key exchange (NAKE) protocol based on elliptic curve cryptography for session initiation protocol, which provides provable security in CK security model. This paper, however, demonstrates that Wu et al.'s NAKE protocol is vulnerable to off-line password guessing attacks and then presents an improved protocol in order to isolate such a problem.