Abstract: In order to address the anonymous authentication problem in mobile IP registration, a mobile IP registration protocol with user anonymity is proposed. To construct its temporary identity (TID) in the registration request message, the mobile node (MN) hashes the home agent (HA)s identity together with a newly established Diffie-Hellman key and performs a bitwise XOR over the MNs real identity and the hashed value. Then HA recalculates the hash value and XORs it with the received TID to derive the MNs true identity. The user anonymity and untractability are achieved in the proposed protocol by the TID, which varies with each registration. Theoretical analysis demonstrates that the proposed protocol accomplishes both strong anonymity and mutual authentication among three mobile IP entities. Compared to the anonymous wireless authentication protocol proposed by Peng et al., the proposed protocol reduces the computation load at the MN.

Key words: mobile IP, user anonymity, registration