Switching matrix

摘要

A deciphering unit having input and output matrices connected to a master shift register to permit flexible access to its stages. The output matrix allows selection of four register positions in the master shift register from which data is fed to a correspondence generator where it is partially descrambled. Subsequently, the input matrix allows selection of four input register positions for the partially descrambled data, and one input register position for serial key shift register data. A comparison matrix selects eight bit positions to allow comparison of the descrambled master shift register data with a predetermined eight bit word. Upon favorable comparison a four bit word is transmitted to a base interrogating station for identification. Also, the same apparatus can be used for enciphering by shifting the data in the master shift register in a reverse manner.