Patent ID: 8533471

Claim:
A method for preparation of at least one mobility key for cryptographic securing of mobility signaling messages for a home agent, comprising: establishing a radio connection between a mobile subscriber end device and an access network, by an authentication proxy server of an intermediate network forwarding at least one authentication message, containing an authenticating subscriber identity, between the access network and a home network of a subscriber to authenticate the subscriber, and saving the authenticating subscriber identity, by the authentication proxy server, upon successful authentication by an authentication server of the home network; receiving, by the home agent, a registration request message originating from a registering subscriber end device and containing a registering subscriber identity; sending a key request message for a mobility key from the home agent to the authentication proxy server, with the key request message containing the registering subscriber identity; and deriving the mobility key by the authentication proxy server for the home agent when determining that the registering subscriber identity is consistent with a stored subscriber identity saved by the authentication proxy server in accordance with said establishing the radio connection, where the authentication proxy server determines whether the authentication server is lacking mobile IP support.