Data recording device, and method of processing data recording device

A host storing host key information, the host comprising:

• processing circuitry configured to perform a key exchange/authentication process with a medium by
• generating a first random number, and sending, to a medium, the first random number and host certification information;
• receiving, from the medium, a second random number, medium certification information, a first value, and unique ID information, the first value being calculated using a base point of an elliptic curve and a third random number, the unique ID information being generated by executing a one-way function calculation based on controller key information and controller identification information stored in the medium, the unique ID information being used in a signature process using medium key information;
• generating a fourth random number, and calculating a second value using the fourth random number and the base point of the elliptic curve;
• and
• generating shared key information based on the first value and the fourth random number to complete the key exchange/authentication process and establish a secure channel, the shared key information being shared between the host and the medium.