| 摘要 |
Methods and apparatus for encoding compressed data streams efficiently, and methods and apparatus for decoding the encrypted data streams are disclosed. In an encoder (10'), an incoming data stream is fed to a Huffman coding block (10) that performs data compression. The output codewords are fed to a forward error correction block (30). The data blocks are fed to an error insertion block (32), which inserts a one-bit error in each data block. The parity data is fed to a first encryption block (34) that produces encrypted parity data. The output of the error insertion block (32), the encrypted parity data, and a synchronization word output by a sync generator (50) are fed to a multiplexer (48). A seed generator block (36) generates random numbers for use by the first encryption block (34) as seeds for encryption the parity data. A multisession key register (40) stores a multisession key employed as a seed in a second encryption block (38) to encrypt the random number seed. A secret serial number (SSN) read from a database (46) and stored in an SSN register (44) is employed by a third encryption block (42) as a seed for encrypting the multisession key. A decoder (14') receives the multiplex data and recovers the original data. |
