Key whitening

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In cryptography, key whitening is a technique intended to increase the security of an iterated block cipher. It consists of steps that combine the data with portions of the key.

Details

Key whitening using the xor-encrypt-xor technique: a (short) Key is made longer with Key1 and Key2 parts

The most common form of key whitening is

XOR before the first round and after the last round of encryption
.

The first block cipher to use a form of key whitening is

brute force attack, increasing the effective size of the key without major changes in the algorithm. DES-X's inventor, Ron Rivest
, named the technique whitening.

The cipher

.

See also

References

  • .