LEX is a

stream cipher stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream ( keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream ...

based on the round transformation of

AES AES may refer to: Businesses and organizations Companies * AES Corporation, an American electricity company * AES Data, former owner of Daisy Systems Holland * AES Eletropaulo, a former Brazilian electricity company * AES Andes, formerly AES Gener ...

. LEX provides the same key agility and short message block performance as AES while handling longer messages faster than AES. In addition, it has the same hardware and software flexibility as AES, and hardware implementations of LEX can share resources with AES implementations. Designed by

Alex Biryukov Alex Biryukov is a cryptographer, currently a full professor at the University of Luxembourg. His notable work includes the design of the stream cipher LEX, as well as the cryptanalysis of numerous cryptographic primitives. In 1998, he developed ...

, LEX is a Phase 2 Focus candidate for the

eSTREAM eSTREAM is a project to "identify new stream ciphers suitable for widespread adoption", organised by the EU ECRYPT network. It was set up as a result of the failure of all six stream ciphers submitted to the NESSIE project. The call for primi ...

project. It is not patented. A new revision of LEX protects against a

slide attack The slide attack is a form of cryptanalysis designed to deal with the prevailing idea that even weak ciphers can become very strong by increasing the number of rounds, which can ward off a differential attack. The slide attack works in such a way ...

found in an earlier version.

External links

eSTREAM page on LEX
Stream ciphers {{crypto-stub