Application

Shift registers occur in electronic devices which generate pulses of specified behaviour.

For instance, they are used to produce pseudo-random sequences, that is sequences whose pattern is not easy to detect. To this end it is important to let the period be as high as possible. See a later page of this section for more on the period of a shift register.

Such pseudo-random sequences are used to encrypt binary messages; bit by bit the shift register outputs are added (mod 2) to the message stream, and conversely for decryption.