Patent US 5,282,214

A method and apparatus are disclosed for the efficient generation of cyclic redundancy check (CRC) codes employing CRC generator polynomials of the form (1+x).multidot.f(x). The efficiency is achieved by independently and concurrently generating in parallel a preliminary CRC code word corresponding to f(x) and a term corresponding to (1+x) over a message M(x). The term corresponding to (1+x) is generated in a manner to have either a zero (0) state or a one (1) state. Then, the term corresponding to (1+x) is used to modify the preliminary CRC code word to obtain an overall CRC code word being generated over message M(x). If the term corresponding to (1+x) is a 0 state, then the overall CRC code word is obtained by shifting the bits of the preliminary CRC code word once to the left. If the term corresponding to (1+x) is a 1 state, then the overall CRC code word is obtained by shifting the bits of the preliminary CRC code word once to the left and adding f(x) to the shifted preliminary CRC code word.