Editing Error detection and correction (section)

=== Checksum ===
{{Main|Checksum}}
A ''checksum'' of a message is a [[modular arithmetic]] sum of message code words of a fixed word length (e.g., byte values). The sum may be negated by means of a [[ones'-complement]] operation prior to transmission to detect unintentional all-zero messages.

Checksum schemes include parity bits, [[check digit]]s, and [[longitudinal redundancy check]]s. Some checksum schemes, such as the [[Damm algorithm]], the [[Luhn algorithm]], and the [[Verhoeff algorithm]], are specifically designed to detect errors commonly introduced by humans in writing down or remembering identification numbers.