Communication apparatus, digital signature issuance method and apparatus, and digital signature transmission method

摘要

An initiator shares y_ir with a responder, calculates HASH_I on the basis of y_ir, and sends HASH_I to an IKE proxy server. The initiator receives a digital signature SIG_S generated for HASH_I and the address of the initiator from the IKE proxy server and sends the digital signature SIG_S to the responder.