News of the developments circled the globe, and researchers worldwide became interested in the subject. In 1981, the first cryptology conference, Crypto, was held in California, USA, and has been held there in August every year since.

The Europeans joined the party with the organisation of Eurocrypt, which has been held each spring since 1982.

Cryptology, and particularly public-key cryptology, is based on advanced discrete mathematics, such as Euclid's algorithms, the Chinese remainder theorem, Fermat's little theorem and Euler's phi function. Today, cryptology is an established discipline and the subject is taught at universities around the world.

This book is based on the author’s lecture notes, written for courses taught at the Technical University of Denmark, DTU, since 2001.

Lars Ramkilde Knudsen has been a professor since 1999, and is currently one of the leading cryptologists in Denmark.