Cyclically redundant testing with efficient recalculation of the error-detecting code

摘要

Efficient re-computation of an error detection code such as a CRC is achieved with an original data message (410) that includes a payload (415) and an error detection code (425). The error detection code comprises a value determined according to an error detection formula using the payload. The payload is modified (420) using a payload transformation formula. The error detection code is re-computed (430) from the original error detection code, rather than from the modified payload. The formula for re-computing the error detection code is different from the formula used to originally obtain the error detection formula, and does not use the original payload or the modified payload.