Abstract: Mobile IP is widely used in today's life, and then how is its security ensured? This paper deals mainly with the security aspect of the registration procedure in Mobile IP. We present a timestamp-based registration protocol. The public-key mechanism and timestamp are both used for entity authentication. The private-key mechanism is also used by the mobile node to achieve mutual authentication between itself and home agent, in the case where mobile agent's computational power is limited.

Key words: mobile IP, timestamp, registration protocol