Parity in Computer Science can also be used as an efficient way to create redundancy. For example, if one has several bit strings:
A = 10011001
B = 01010110
C = 10011111
One can calculate A XOR B XOR C = P. P is a
parity byte for A,B,C.
P = 01010000
Now because of the beauty of XOR, A XOR B XOR P = C, and P XOR B XOR C = A. The pattern quickly emerges that if we XOR any three of these four values we get the remaining value. This method insures redundancy of the loss of
any one
value for the cost of one extra value.