Codes and Cryptography

This textbook forms an introduction to codes, cryptography and information theory as it has developed since Shannon's original papers. The first part of the book develops the fundamental ideas of information theory, efficient encoding of messages, and error-correcting codes. In later chapters, the author discusses mathematical models of natural languages and the classic Shannon model of cryptography, before surveying computational complexity and the modern cryptographic methods such as public-key cryptography, password systems and authentication techniques. The book is based on courses given to undergraduate mathematicians and computer scientists at the University of Oxford and contains exercises and solutions.