Patent ID: 8611543

Claim:
A method for providing a Mobile IP (MIP) key for encrypting messages between a subscriber terminal or a Proxy Mobile Internet Protocol (PMIP) client and a home agent, comprising: reviewing an encoded parameter at an authentication server; determining, on the basis of the encoded parameter at the authentication server, whether the subscriber terminal itself supports Mobile IP under terminal-based mobility management or client MIP (CMIP) or whether the subscriber terminal itself does not support Mobile IP under network-based mobility management or PMIP; and providing the Mobile IP key from the authentication server only when the subscriber terminal itself does not support Mobile IP under PMIP, wherein the subscriber terminal is a mobile terminal, the authentication server has two different MIP keys, the home agent is provided with a client MIP key by the authentication server when the subscriber terminal itself supports Mobile IP, and the home agent is provided with a proxy MIP key by the authentication server when the subscriber terminal itself does not support Mobile IP.