A synchronization method and corresponding apparatus for transmitting or storing encrypted data breaks the data into blocks and appends to each block an error detection code which is calculated from the encrypted data block plus a unique sequence number. The sequence number is generated by a local counter...http://www.google.fr/patents/US4654480?utm_source=gb-gplus-shareBrevet US4654480 - Method and apparatus for synchronizing encrypting and decrypting systems
Method and apparatus for synchronizing encrypting and decrypting systems