(1) A function that protects data stored in an auxiliary storage pool from being lost because of the failure of a single disk. When checksum protection is in effect and a disc failure occurs, the system automatically reconstructs the data when the system programme is loaded after the device is repaired. See also device parity protection, mirrored protection.
(2) In TCP/IP, the sum of a group of data associated with the group and used for error checking purposes.