When the external storage itself is replaced by a legitimate old key by a malicious third party, the security IP cannot recognize that it is the old key and can be easily rolled back, that is, the old key is regarded as the legitimate key and operates. An OTP is provided in the SoC, and the version of the key ring is managed in one control table area. Specifically, predetermined information that is updated in synchronization with the key update is written in the management table area of the OTP, and an authentication value is calculated by associating the predetermined information with a key ring including the update key. The calculated authentication value is added and registered when registering the key ring.