checkdigit.crc

Cyclic Redundancy Check.

A block of binary as a form of data validation is appended to a bitstring. This can be easily checked even by very simple circuitry, and can also be used to correct some errors.

WARNING: THIS IS NOT A FAST IMPLEMENTATION OF CRC.

If you want a fast implementation look elsewhere.

Functions

calculate	Adds a parity part onto the end of a block of data.
missing	Calculates missing digits represented by a question mark.
validate	Validates whether the check digit matches a block of data.