Advanced Linear Cryptanalysis of Block and Stream Ciphers

The origins of linear cryptanalysis can be traced back to a number of seminal works of the early 1990s. Since its invention, several theoretical and practical aspects of the technique have been studied, understood and generalized, resulting in more elaborated attacks against certain ciphers, but also in some negative results regarding the potential of various attempts at generalization. This book gives an overview of the current state of the discipline, as well as taking a look at potential future developments, and is divided into five parts. The first part deals with basic assumptions in linear cryptanalysis and their consequences for the design of modern block ciphers; part two explores a theory of multi-dimensional linear attacks on block ciphers; the third part covers how linear attacks can be applied to stream ciphers, and gives an overview of the development of linear attacks as well as a theoretical explanation of their current use. Part four details interesting and useful links between linear cryptanalysis and coding theory, and the fifth and final part discusses how correlation analysis can be conducted at the level of elements of GF (2n) without the need to deal with field representation issues. This book will be of interest to anybody who wishes to explore this fascinating yet complex part of symmetrical cryptanalysis.