Codes and Cryptography

Dominic Welsh's Codes and Cryptography takes a wide approach and explores the mathematical foundations of this field, considering information theory, entropy, and the encoding of messages. From these roots in information and communication theory, Welsh then moves on to topics in cryptography, including public key cryptography and digital signatures. The text also offers practice exercises along with their solutions.

There is plenty of mathematics here, making this a book for specialists (a result of the author's experience teaching undergraduates at Oxford). Between the formulas, though, the author conveys a genuine enthusiasm for his subject and for the history of cryptography. The text includes an extensive bibliography of sources in the field.