ENCRYPTION/RECORDING DEVICE, REPRODUCTION DEVICE AND PROGRAM

摘要

An encryption/recording device, a reproduction device, and a program capable of eliminating possibility of capacity shortage of a protection region attributed to increase of the information amount and the number of content keys. Unlike the conventional way, an encryption user identifier Enc_m (IDu, IDm) is recorded in a protection region (12a) of a key storage medium (10a). The encryption user identifier Enc_m (IDu, ID m) is fixed information and has a characteristic not increasing the data amount in association with the use format. Accordingly, there will not arise capacity shortage of the protection region.