Patent ID: 8542838

Claim:
A method for generating and distributing a mobile IP (MIP) key, comprising: receiving, by a foreign agent (FA), an MIP registration request from a mobile node (MN), wherein the MIP registration request carries a first authentication extension (AE) between the MN and a home agent (HA), and the first AE is generated according to a first key between the MN and the HA computed by using an IP address replacement value of the HA, wherein all bits of the IP address replacement value of the HA are 0 or all bits of the IP address replacement value of the HA are 1; transmitting, by the FA, the MIP registration request to the HA; receiving, by the HA, the MIP registration request from the FA; obtaining, by the HA, from an authentication server, the first key and a second key between the MN and the HA computed by using an IP address of the HA; validating, by the HA, the first AE in the registration request by using the first key, and transmitting an MIP registration report to the FA after the successful validation, wherein the registration report carries a second AE generated according to the second key; and transmitting, by the FA, the registration report carrying the second AE to the MN, so that the MN can validate the second AE by using the second key.