KEY EXCHANGE DEVICE, KEY EXCHANGE SYSTEM, KEY EXCHANGE METHOD, AND KEY EXCHANGE PROGRAM

摘要

On the assumption that i≠s, j is the number of times a key exchange is performed, and k is any one of integers greater than or equal to 0 and less than j, a key exchange device includes: a shared secret key storage in which shared secret information mk_i^k which is information different from a secret key of the key exchange device is stored; an authentication information addition unit that generates authentication information σ_i, by which authentication is performed and falsification is detected, for key exchange information e_i, which is output to the outside, by using the shared secret information mk_i^k; and an authentication information verification unit that receives key exchange information e_s and authentication information σ_s corresponding to the key exchange information e_s from the outside, verifies the authentication information σ_s using the shared secret information mk_i^k, and, if the authentication information σ_s is not successfully verified, stops a key exchange, and the shared secret information mk_i^k is a value that is used in a generation process in a key exchange.