Linear cryptanalysis

The linear cryptanalysis is a common form of cryptanalysis based on the linear approximation of the most likely code for breaking of block encryption methods. This method was published by Mitsuru Matsui ( one of the developers of the Misty1 encryption algorithm) 1993.

This technique was first used in the study of FEAL encryption. Later, Matsui also published an attack on the Data Encryption Standard ( DES), which eventually became the first public publication of an experimental cryptanalysis. This attack is hardly applicable in practice, since it requires 247 known Klartext-/Chiffrat-Paare for a 16 - round DES.

Other variants of the linear cryptanalysis have been developed for both block and for stream ciphers. Therefore, in newly designed algorithms usually checked their security against linear cryptanalysis.

The linear cryptanalysis attack is one of the most common ways to block ciphers, the other is the differential cryptanalysis.