AUTHENTICATION ENTITY DEVICE, VERIFICATION DEVICE AND AUTHENTICATION REQUEST DEVICE

摘要

A verification device transmits challenge information to a first entity device, and for each authentication context received in return, verifies that challenge information identical to the challenge information transmitted in advance is described, to thereby confirm that the authentication context is the current one. As a result, a repetitive attack in which the past authentication context is repeatedly used is prevented and the security against repetitive attacks is improved.