Key distribution system for protection of route-update notification in micromobility networks

A router in a mobile communication network comprising:

• means for using authentication information established for each mobile terminal to authenticate mobile terminal route-update notifications that are communicated from mobile terminals after encryption;
• and
• route information management means for holding authentication information for the mobile terminals, verifying the route-update notifications communicated from these mobile terminals, and managing their route information;
• wherein said route information management means includes means which, when it receives a route-update notification, if the route information management means is determined not to hold the authentication information corresponding to the originating mobile terminal, requests and acquires the authentication information in question from a connected router containing the authentication information located prior to the top-level router, where the top-level router manages the authentication information of all mobile terminals and distributes it in response to requests from other routers.

A program storage medium readable by a computer, tangibly embodying a key distribution program of instructions executable by the computer to control the computer to function for protecting route-update notifications and which controls the computer to distribute, to the routers in a mobile communication network, the authentication information established for each mobile terminal, which is used by the routers to authenticate mobile terminal route-update notifications that are communicated from the mobile terminals after encryption, comprising:

• executing route information management processing whereby routers within a routing path intermediate a top-level router and a first router closest a mobile terminal each hold authentication information for the mobile terminals, verify the route-update notifications communicated from these mobile terminals, and manage their route information;
• and
• in said route information management processing, executing processing whereby, when a route-update notification is received, if a router in the routing path intermediate the top-level router and the first router is determined not to hold the authentication information corresponding to the originating mobile terminal, the authentication information in question is requested and acquired from the top-level router, where the top-level router manages the authentication information of all mobile terminals and distributes it in response to requests from routers.

A key distribution method for protecting route-update notifications which distributes, to the routers in a mobile communication network, the authentication information established for each mobile terminal, which is used by the routers to authenticate mobile terminal route-update notifications that are communicated from the mobile terminals after encryption, including:

• a route information management step in which a base station has been in radio transmission with an originating mobile terminal, the base station being connected to a first router, and via plural subsequent routers to a top-level router, wherein each of the top-level router, the first router, and the plural subsequent routers holds authentication information for the originating mobile terminal that has been previously provided from the top-level router responsive to a prior authentication information request by the first router;
• and
• responsive to a route-update notification received from a requesting router, if a router of the plural subsequent routers receives the route-update notification and is determined to hold the authentication information corresponding to the originating mobile terminal, that router responds with the authentication information in question, without requesting the authentication information from the top-level router, and distributes the held authentication information to the requesting router.

An authentication information distribution system in a packet-based mobile terminal system, comprising:

• a top-level router;
• plural base stations;
• and
• plural routers, the plural routers, one through another, connecting each of the base stations to the top-level router, wherein,
• a first base station, in communication connection with a mobile user terminal, receives an update notification from the terminal and transmits a request for authentication information, required to authenticate the update notification, to the top-level router via a first router connected to the first base station and via the plural routers connecting the first router to the top-level router, and
• each of the plural routers, connecting the first router to the top-level router, that receives the request for authentication information, i) determining if the requested authentication information corresponding to the terminal is already stored within that router, ii) upon determining the authentication information is already stored, sending the authentication information already stored to the first base station without requesting the authentication information from the top-level router, and iii) if the authentication information is determined not to be already stored, requesting the authentication information from the top-level router.