Patent ID: 7174018

Claim:
A method for securely communicating to a mobile node on a communications system having a home network for the mobile node and at least one foreign network comprising the steps of: requiring at least one security association between the home network and the foreign network, wherein the home network has at least one home agent network server; establishing at least one security association between the mobile node and the foreign network using a registration reply message to transmit a public key, said registration reply message originating at the home agent network server and transmitted to the mobile node to acknowledge registering the mobile node care-of address with the home agent network server; requiring that an information packet received by the home network be encrypted with an encryption mechanism; transmitting the information packet from the mobile node using the security associations to support secure communications from the mobile node; routing the information packet through a secure messaging gateway that includes a firewall and an AAA server performing authentication and accounting functions; coupling a service level agreement broker to the foreign network, separate from any AAA server on either the home network or the foreign network, to support establishment and maintenance of a plurality of security associations for multiple networks and multiple nodes used in communications on the communications system to include establishing and maintaining a single service level agreement for communications among multiple networks and multiple nodes; and decoding information from the encrypted information packet at the home network to retrieve the information.