XOR

(eXclusive OR) A Boolean logic operation that is widely used in cryptography as well as in generating parity bits for error checking and fault tolerance. XOR compares two input bits and generates one output bit. The logic is simple. If the bits are the same, the result is 0. If the bits are different, the result is 1.

 

Several Symbols

Various symbols are used to designate the XOR operation including a + sign inside a circle, an underlined “V” and the caret (^). See cryptography, RAID and or.

XOR in Cryptography

This example uses XOR and the same “secret key” to encrypt and decrypt. In practice, XOR is not used quite as simply as this. It is used in combination with different techniques and other ciphers to provide the complete encryption algorithm.