In one embodiment, a write/read apparatus includes an external interface section for data input; an external interface section for data output; a memory for temporarily storing the data that is input through the external interface section for data input and written on the recording medium and the data that is read from the recording medium and sent to the outside through the external interface section for data output; an address generating section for generating unique addresses associated with physical block addresses of the recording medium; a flag generating section for generating flags for prohibiting overwriting of the data to be written on the recording medium; and a processing section for adding the unique addresses generated in the address generating section to the data that is stored in the memory and that is to be written on the recording medium. The data with the addition of the flags generated in the flag generating section and the unique addresses is written on the recording medium.