| 摘要 |
<p>An apparatus and method for providing two levels of copy protection, including a first method for copy protection, including a key, and a second method for copy protection. One level of copy protection is a moderately secure level to allow decrypting a medium- to high-bandwidth data stream without significant delay of the data stream. The second level of copy protection can be highly secure but can be utilized less often and so can be decrypted more slowly. One useful combination is to use a key encryption scheme for the first level of copy protection of a primary data stream, then to use the second protection scheme to securely transfer the first level key from a protected storage location to a decoding location. Encoded primary data can be stored on a removable media, together with the decryption key stored in a special location. The media drive unit can access the special location and, using the second level copy protection scheme, transfer the key securely to a descrambling unit. The first level copy protection can involve selective reordering of data subunits within a data unit according to a scrambling vector, then encoding the scrambling vector using the first key, and storing the encoded scrambling vector with the corresponding data unit.</p> |
