| 摘要 |
The enciphering section of an enciphering/deciphering system includes a random number generator, a primary code memory and a multiplex unit in addition to the actual enciphering unit. The deciphering section includes a deciphering unit, a primary code memory and a demultiplex unit. At the beginning of each transmission, and after disturbances, the enciphering and deciphering sections are first synchronized by means of a synchronization sequence. Then a random address is produced by the random number generator for a primary code, and a randomly determined auxiliary code is also selected. The address and the auxiliary code are then transmitted and the primary and auxiliary codes are loaded into the enciphering and deciphering units. The randomly controlled, statistical selection of the primary code simplifies the code management and thus the operation of the system. |
