Linear Cryptanalysis

Question

What do you mean by the term Linear Cryptanalysis? Illustrate in brief.

Answer 1

Linear cryptanalysis was initially devised by Matsui and Yamagishi in an attack on FEAL. This was extended by Matsui to attack DES. The linear cryptanalysis is an identified plaintext attack and employs a linear approximation to explain the behavior of the block cipher. Given adequate pairs of plaintext and equivalent ciphertext, bits of information regarding the key can be received and raised amounts of data will generally provide a higher probability of success.