MULTI-LEVEL ENCRYPTION COMMUNICATING METHOD AND SYSTEM

摘要

PROBLEM TO BE SOLVED: To perform re-synchronization by detecting asynchronization of a Running key. SOLUTION: The transmitting side transmits the multi-level encrypted synchronous data indicating location of the Running key used for encryption by embedding the same in a plaintext. The receiving side verifies synchronization of the Running key by detecting the synchronous data from the signal decoded by the Running key and transmits a synchronization verification signal to the transmitting side. The transmitting side re-synchronizes the Running key by recognizing asynchronization of the Running key when the synchronization verification signal is not received under the predetermined condition. This re-synchronization process starts generation of the Running key from the location progressed as much as a constant value from the location of the Running key corresponding to the synchronization data recorded at the time of transmission. COPYRIGHT: (C)2008,JPO&INPIT