| 摘要 |
A method and a system for coding digital data represented by source symbols (S<SUB>i</SUB>) with an error-correction code. The error-correction code generates parity symbols (P<SUB>j</SUB>) based on, for each parity symbol, several source symbols and at least one parity symbol of preceding rank. At least a part of the source symbols is submitted to at least a first ciphering. The obtained ciphered symbols and the rest of the unciphered source symbols are submitted to the error-correction code. Accordingly, the present disclosure improves the security of the transmitted data. The present disclosure is also compatible with the management of different groups of users. The present disclosure is well adapted to large-scale broadcasting systems and provides a solution compatible with any ciphering algorithm. In addition, the present disclosure is particularly well adapted for use with LDPC-type error-correction codes. |
