Contents information recording method and contents information recording unit

摘要

Enciphered contents information enciphered with a predetermined contents key is recorded from a medium A to a medium B. At this time, an ID(B) of a copy destination medium B is read on the medium A and first enciphered key information enciphered with the ID(A) is deciphered on the medium A. Then, on the medium A, the deciphered information is reenciphered according to ID of the copy destination medium so as to obtain second enciphered key information and this second enciphered key information is sent to the medium B. Alternatively, the first enciphered key information is outputted from the medium A to the copy destination medium B. On the medium B, the first enciphered key information is deciphered with ID(A) of the copy source medium A obtained from the medium A, that deciphered information is reenciphered with the ID(B) of the medium B so as to obtain second enciphered key information and then that second enciphered key information is recorded in the medium B.