Method and appts. for data recording and reproducing, data recording and/or reproducing system

使用本发明，即使数据处理设备和盘片记录和/或再现设备间传送的数据被监视，也能有效防止被复制以保护数据。盘片记录和/或再现设备(10)的写入ID生成器(20)对数据记录产生独立的写入ID，传送写入ID到数据处理设备(100)的加密器(102)。加密器(102)对用作加密内容数据的密钥信息的内容ID和限制或禁止复制的数据控制信息使用基于写入ID的加密密钥进行加密。加密数据经I/F(101)和I/F(19)传到盘片记录和/或再现设备(10)的加密器(24)上，使用基于盘片ID的加密密钥与写入ID一起被加密，记录到盘片(30)上。 Even though data transmitted between a data processing apparatus and disc recording and/or reproducing apparatus is monitored, copying the data is effectively prevented and the data can be protected. A write ID generator 20 of a disc recording and/or reproducing apparatus 10 generates independent write ID for each recording of data, and transmits the write ID to an encryptor 102 of a data processing apparatus 100. The encryptor 102 encrypts contents ID to be used for key information for encrypted contents data and data control information to restrict or prohibit copy by the use of an encrypting key based on the write ID. The encrypted data are transmitted to an encryptor 24 of the disc recording and/or reproducing apparatus 10 via an I/F 101 and I/F 19, and encrypted along with the write ID by the use of an encrypting key based on disc ID, and recorded to a disc 30.