Modication of Internet Key Exchange Resistant against Denial-of-service

The rst phase of Internet Key Exchange (IKE) is an authenticated version of Di e-Hellman (DH) key-agreement. Since the authentication is computationally expensive, computational burden caused by malicious requests may exhaust the CPU resource of the target. Attackers can also abuse inappropriate use of Cookies and exhaust the memory resource of the target. In search of resistance against these Denial-ofService (DoS) attacks, this paper modi es threepass IKE Phase 1. The DoS-resistance is evaluated in terms of the computational cost and the memory cost caused by bogus requests.