DES-X

From CryptoDox, The Online Encyclopedia on Cryptography and Information Security

DES-X (or DESX) is a variant on the DES (Data Encryption Standard) block cipher intended to increase the complexity of a brute force attack using a technique called key whitening. In DESX, the input plaintext is bitwise XORed with 64 bits of additional key material before encryption with DES and the output is also bitwise XORed with another 64 bits of key material.

Implementation

• Crypto++ - A free C++ class library of cryptographic schemes

External References

• What is DESX?
• Joe Kilian and Phillip Rogaway, How to protect DES against exhaustive key search, Advances in Cryptology - Crypto '96, Springer-Verlag (1996), pp. 252–267.
• P. Rogaway, The security of DESX, CryptoBytes 2(2) (Summer 1996).