Mobile IP proposed by IETF supports continuous services for a mobile node (MN) based on its capability to roam around foreign domains [1]. Recently the rapid growth of wireless technology and its use in coordination with the Internet require a very careful look at issues regarding the security. As a large portion of 785-million world Internet users access such technologies in the context of providing security demanded services, it is essential to recognize the potential threats in wireless technologies. For this reason, IETF suggests that the existence of some servers capable of performing the authentication, authorization, accounting (AAA) services could help [4, 5, 6, 7]. In this paper, we propose an Extended IDentification Key (EIDK) mechanism based on IDK with Authentication Value (AV) that can reduce the number of signaling messages and thus signaling delay for services even in handoffs while maintaining the similar level of security to the previous works [10, 11]. The performan...