Patent ID: 7661001

Claim:
An encrypting apparatus ( 10 ) forming a master machine and comprising: a first memory ( 13 ) for storing a machine ID peculiar to the present encrypting apparatus ( 10 ); a second memory ( 14 ) for storing encryption key information corresponding to the machine ID peculiar to the present encrypting apparatus ( 10 ); first means ( 12 ) responsive to insertion of a recording medium ( 20 ) into the present encrypting apparatus ( 10 ); wherein the recording medium ( 20 ) can be inserted into and ejected from the present encrypting apparatus ( 10 ) and includes a recording-medium-ID memory ( 21 ) for storing a recording-medium ID being peculiar to the recording medium ( 20 ) and being preset to a value having a one-to-one correspondence relation with a machine ID peculiar to an encrypting apparatus, a machine-ID memory ( 22 ), and an encryption-key-information memory ( 24 ); the first means ( 12 ) being for comparing the machine ID stored in the first memory ( 13 ) and the recording-medium ID stored in the recording-medium-ID memory ( 21 ) within the recording medium ( 20 ) to decide whether or not the recording medium ( 20 ) corresponds to the present encrypting apparatus ( 10 ); and second means ( 11 , 12 ) for in a case where the recording medium ( 20 ) corresponding to the present encrypting apparatus ( 10 ) is inserted into the present encrypting apparatus ( 10 ), transmitting the machine ID from the first memory ( 13 ) and storing the transmitted machine ID into the machine-ID memory ( 22 ) within the recording medium ( 20 ), and transmitting the encryption key information from the second memory ( 14 ) and storing the transmitted encryption key information into the encryption-key-information memory ( 24 ) within the recording medium ( 20 ), and for in a case where another recording medium corresponding to an encrypting apparatus forming a slave machine different from the master machine is inserted into the present encrypting apparatus ( 10 ), transmitting the machine ID from the first memory ( 13 ) and storing the transmitted machine ID into a machine-ID memory within said other recording medium, and transmitting the encryption key information from the second memory ( 14 ) and storing the transmitted encryption key information into an encryption-key-information memory within said other recording medium.