Patent ID: 8874917

Claim:
A storage system comprising: a host device; and a secure storage including: a memory provided with a protected first storing region which stores secret information sent from the host device, and a second storing region which stores encoded contents; and a controller configured to carry out authentication processing for accessing the first storing region, wherein the host device and the secure storage produce a bus key which is shared only by the host device and the secure storage by the authentication processing, and which is used for encoding processing when information is sent and received between the host device and the secure storage, the host device produces a message authentication code including a message which can be stored in the secure storage based on the bus key in a state where the authentication processing is completed, and sends the produced message authentication code to the secure storage, the secure storage stores the message included in the message authentication code in accordance with instructions of the host device, and the host device verifies whether the message stored in the secure storage is intended contents.