Algebraic CryptanalysisIntroduction: How to Use this Book. Cryptanalysis. The Block Cipher Keeloq and Algebraic Attacks. The Fixed Point Attack. Iterated Permutations. Stream Ciphers. Linear Systems Mod 2. Some Basic Facts about Linear Algebra over (2). The Complexity of (2) Matrix Operations. On the Exponent of Certain Matrix Operations. The Method of Four Russians. The Quadratic Sieve. Polynomial Systems and Satisfiability. Strategies for Polynomial Systems. Algorithms