longitudinal parity (storage, communications) An extra byte (or word) appended to a block of data in order to reveal corruption of the data. Bit n of this byte indicates whether there was an even or odd number of "1" bits in bit position n of the bytes in the block. The parity byte is computed by XORing the data bytes in the block. Longitudinal parity allows single bit errors to be detected.
Last updated: 1996-03-01
