An integrity protection measure that is used primarily in data storage and networking protocols by adding the bytes or some other string of data components and storing the resulting value. Afterward, an individual having the checksum can confirm that the message was unchanged by performing the same operation on the data—in essence, checking the sum. Some errors—such as reordering the bytes in the message, putting in or taking out zero-valued bytes, and having multiple errors that increase and decrease the checksum in opposite directions—cannot be detected using the checksum integrity protection measure. To avoid this problem, cryptographic checksums have been introduced.

See Also: Bytes; Cryptography or “Crypto.”