KEY MANAGEMENT DEVICE, APPLICATION SIGNATURE ATTACHMENT DEVICE, RECEPTION TERMINAL AND PROGRAM THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide an application authentication system which updates a signature key by segments such as units of applications, units of versions, etc.SOLUTION: An application authentication system S comprises: a key management server 1 which generates a verification key and a signature key by a signature system using a verification key and a signature key which is updated on the basis of an application ID; an application signature attachment server 5 which attaches an application ID and a signature to an application; an application distribution server 7 which stores and distributes the application; and a reception terminal 9 which uses the application. The key management server 1 updates the application ID by receiving an instruction to update any of a plurality of segments composing the application ID from the application signature attachment server 5, and generates difference information for updating the corresponding signature key. Then, the application signature attachment server 5 updates the signature key by the difference information.