The server device for authentication, illegitimate terminal method of detection, through the illegitimate terminal detection system

摘要

PROBLEM TO BE SOLVED: To provide a server device or the like for authentication capable of detecting that an identical terminal key is stored in a plurality of terminals, and of detecting which terminal key of legitimate terminals is stored in an unauthorized terminal.;SOLUTION: A DVD terminal 20 makes a request for sending a sub-content to an authentication server 40 (in this case, attaches the "model name and serial number" of the DVD terminal 20) (S302). The authentication server 40 generates a random number R (S304) and sends it to the DVD terminal 20 (S306). The DVD terminal 20 reads a terminal key and a terminal ID that are stored in a terminal information memory unit 25, encrypts the received random number R using a terminal key (SK_X) (S308) and sends it and the terminal ID (ID_X) to the authentication server 40 (S310). The authentication server 40 verifies the random number R and the terminal ID that are received from the DVD terminal 20 and encrypted, and authenticates whether the DVD terminal 20 is the valid terminal or not (S312).;COPYRIGHT: (C)2005,JPO&NCIPI