Title: Linear Cryptanalysis of Long-Key Iterated Cipher with Applications to Permutation-Based Ciphers
Abstract: In this talk I will discuss linear cryptanalysis of block ciphers based on iterated structures. The theory for long-key block ciphers is well developed and statistics estimates can be derived based on the signal-noise model. This theory has been applied to ciphers with key-schedules that imitate long-key properties. Now I will focus on extreme key-schedules such as known-key ciphers, and show how to apply the known properties of a long-key cipher to permutation based ciphers such as EM.