ENCIPHERING METHOD, DECIPHERING METHOD, RECORDING AND REPROD UCING METHOD, DECIPHERING DEIVED, DECIPHERING UNIT DEVIC...

摘要

On a recording medium, first information obtained by enciphering data with the first key and second information obtained by enciphering the first key with each of the predetermined second keys are recorded. A deciphering method is characterized by comprising the steps of inputting the first and second information (S34, S32), deciphering the first key using at least one of the second keys (S33), determining by a specific method that the obtained first key is correct (S33), and then deciphering the data using the first key to obtain the data (S35).