Patent ID: 7095857

Claim:
A key distribution system 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, comprising: a top-level router for managing the authentication information of all mobile terminals and for distributing the authentication information in response to requests from other routers connecting the top-level router to a first router closest to an originating mobile terminal; wherein each of said other routers, in a routing path intermediate the top-level router and the first router, comprises route information management means for holding authentication information for the mobile terminals, verifying the route-update notifications communicated from the originating mobile terminal, and managing the route information; and wherein said route information management means comprises means which, when receiving a route-update notification, makes a determination if the authentication information corresponding to the originating mobile terminal is held, and if the route information management means does not hold the authentication information corresponding to the originating mobile terminal, requests and acquires the authentication information in question from said top-level router.