Abstract: Passing messages between two virtual machines that use a single multicore processor having inclusive cache includes using a cache-based covert channel. A message bit in a first machine is interpreted as a lowest level cache flush. The cache flush in the first machine clears a L1 level cache in the second machine because of the inclusiveness property of the multicore processor cache. The second machine reads its cache and records access time. If the access time is long, then the cache was previously cleared and a logical 1 was sent by the first machine. A short access time is interpreted as a logical 0 by the second machine. By sending many bits, a message can be sent from the first virtual machine to the second virtual machine via the cache-based covert channel without using non-cache memory as a covert channel.

Abstract: The invention concerns a method and a system for encoding digital data (DATA) represented by source symbols, with an error correcting code generating parity symbols from, for each parity symbol, a plurality of source symbols and at least one parity symbol of preceding rank, including at least encrypting once (54) at least one first value (P1) into several encrypted values and integrating at least one combination (P1,j) of said encrypted values to compute (55) at least one part (P2 . . . Pn?k) of said parity symbols.

Abstract: A method and a system for coding digital data represented by source symbols (Si) with an error-correction code. The error-correction code generates parity symbols (Pj) 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.

Abstract: The invention concerns a method and a system for encoding digital data (DATA) represented by source symbols, with an error correcting code generating parity symbols from, for each parity symbol, a plurality of source symbols and at least one parity symbol of preceding rank, including at least encrypting once (54) at least one first value (P1) into several encrypted values and integrating at least one combination (P1,j) of said encrypted values to compute (55) at least one part (P2 . . . Pn-k) of said parity symbols.

Abstract: A method and a system for coding digital data represented by source symbols (Si) with an error-correction code. The error-correction code generates parity symbols (Pj) 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.