A computer readable memory having stored thereon an operation program for a medium drive apparatus connected to an information processing apparatus for performing recording and reproduction on and from a recording medium in accordance with a request from the information processing apparatus, the operation program causing the medium drive apparatus to performing:
- performing an operation as a reproduction only mode wherein a reproduction operation for the recording medium in accordance with a reproduction request from the information processing apparatus is executed but a recording operation on the recording medium in accordance with a recording request from the information processing apparatus is not executed;
- performing an authentication process with the information processing apparatus, in which the authentication process determines whether an access request or write command for allowing recording is acceptable;
- and
- changing operation mode from the reproduction only mode to a recording and reproduction mode in response to success in authentication by the authentication process to perform the recording operation and the reproduction operation on and from the recording medium in accordance with the reproduction request and the recording request from the information processing apparatus,
- in which the authentication process includes determining an authentication identifier key based on an internal random number in response to a request received from the information processing apparatus, notifying the information processing apparatus of the authentication identifier key, and verifying validity of a received authentication identifier produced by the information processing apparatus from the authentication identifier key,
- in which in response to turning on power to the medium drive apparatus and insertion of the recording medium, the operation as the reproduction only mode is performed without performing the authentication process such that the medium drive apparatus is automatically placed in the reproduction or read only mode when the power is applied thereto and the recording medium is inserted, and
- in which in response to a failure in the authentication by the authentication process when the operation mode is in the reproduction only mode, the operation mode continues in the reproduction only mode.