QUASI RANDOM BINARY SEQUENCE GENERATOR

PURPOSE: To enhance the degree of non-predictability by loading correctly a re-initialization word to a shift register means. CONSTITUTION: Two re-circulation groups are formed around shift registers S, T in a normal operating state by means of switches SW1-SW4. The switches SW1-SW4 can be switched to loading positions from the positions shown in the figure, and in these loading positions, the output of the register S is fed to the input of the register T, and zero is fed to inputs of all logic gates G to which the output of the register is always connected. Then a 60-bit re- initialization word is fed to a load input terminal of a switch operated by a clock signal via all of 60-sets of register stages. Thus, the normal operation is conducted correctly and even when contents of the registers are known arbitrarily and instantly, an output of the generator cannot be predicted.