Patent ID: 7400465

Claim:
A recording/reproducing apparatus for recording/reproducing a recording medium cartridge, the apparatus comprising: a Cyclic Redundancy Check (CRC) code producing unit which when recording, produces a first CRC code from first data for inspection made by coupling input data input from outside and a recording/reproducing apparatus unique key stored in said apparatus, and when reproducing, produces a second CRC code made from second data for inspection by coupling data read out from a recording medium and the unique key; a recording/reproducing unit which when recording, writes said input data and first CRC code in said recording medium and when reproducing, reads out data recorded in said recording medium and said first CRC code; and a CRC code inspection unit which when reproducing, compares said first CRC code with said second CRC code, thereby inspecting whether or not both codes accord, wherein data authenticity recorded in said recording medium is determined based on an inspection result of said CRC code inspection unit.