Patent ID: 8447981

Claim:
A method for generating and distributing Mobile IP (MIP) security key after Re-Authentication, comprising: generating, by an Authentication Authorization Accounting (AAA) Server and a Mobile Station (MS), an Extended Master Session Key (EMSK) that is new during a Re-Authentication process; generating, by the MS, a new first Mobile IP (MIP) security key for the MS according to the EMSK, and replacing the corresponding old first MIP security key with the new first MIP security key; and receiving, by a Home Agent (HA), new second MIP security key information for the HA which is sent by the AAA Server actively; or requesting, from the AAA Server, the new second MIP security key information for the HA, and replacing the corresponding old second MIP security key that is locally stored with the new second MIP security key that is sent by the AAA Server actively or requested from the AAA Server, wherein the new second MIP security key information is the EMSK or is derived from the EMSK.