| 摘要 |
<p>Distribution of digital information, in particular audio, is controlled as follows. An information carrier (11) like a CD is distributed which has at least part of the digital information encrypted using an encryption key. A decryption key corresponding to the encryption key is also distributed to the user, e.g. on a reserved area of the CD. The user (32) reproduces the audio on a player (31), which decrypts the information using the key. However, at least part of the information is only reproduced after a Personalized Access Code PAC (40) is received by the player. The PAC is generated at a remote access center (33), e.g. an internet site. A database (34) connected the center and a player memory hold a player identifier and secret player key. The user transmits the player identifier and an information identifier identifying the CD to the access center, and the access center calculates the PAC using the identifier and the secret player key. The PAC is transmitted to the player which verifies the PAC using its own secret player key, and enables the reproduction of PAC protected parts of the information.</p> |
