Linear Cryptanalysis concept

Question

What do you mean by the term Linear Cryptanalysis?

Answer 1

Linear cryptanalysis was first invented by Matsui and Yamagishi in an attack on the FEAL. It was expanded by Matsui to attack DES. Linear cryptanalysis is a well-known plaintext attack and employs a linear approximation to explain the behavior of the block cipher. Given adequate pairs of plaintext and corresponding cipher text, bits of information regarding the key can be obtained and increased amounts of data will generally give a higher probability of the success.