About the Book

Foreword by Bart Preneel

Academic research in cryptology started in the mid-1970s; today it is a mature research discipline with an established professional organization (IACR, International Association for Cryptologic Research), thousands of researchers, and dozens of international conferences. Every year more than a thousand scientific papers are published on cryptology and its applications.

Until the 1970s, cryptography was almost exclusively found in diplomatic, military and government applications. During the 1980s, the financial and telecommunications industries deployed hardware cryptographic devices. The first mass-market cryptographic application was the digital mobile phone system of the late 1980s. Today, everyone uses cryptography on a daily basis: Examples include unlocking a car or garage door with a remote-control device, connecting to a wireless LAN, buying goods with a credit or debit card in a brick and mortar store or on the Internet, installing a software update, making a phone call via voice-over-IP, or paying for a ride on a public transport system. There is no doubt that emerging application areas such as e-health, car telematics and smart buildings will make cryptography even more ubiquitous.

Cryptology is a fascinating discipline at the intersection of computer science, mathematics and electrical engineering. As cryptology is moving fast, it is hard to keep up with all the developments. During the last 25 years, the theoretical foundations of the area have been strengthened; we now have a solid understanding of security definitions and of ways to prove constructions secure. Also in the area of applied cryptography we witness very fast developments: old algorithms are broken and withdrawn and new algorithms and protocols emerge.

While several excellent textbooks on cryptology have been published in the last decade, they tend to focus on readers with a strong mathematical background. Moreover, the exciting new developments and advanced protocols form a temptation to add ever more fancy material. It is the great merit of this textbook that it restricts itself to those topics that are relevant to practitioners today. Moreover, the mathematical background and formalism is limited to what is strictly necessary and it is introduced exactly in the place where it is needed. This ``less is more'' approach is very suitable to address the needs of newcomers in the field, as they get introduced step by step to the basic concepts and judiciously chosen algorithms and protocols. Each chapter contains very helpful pointers to further reading, for those who want to expand and deepen their knowledge.

Overall, I am very pleased that the authors have succeeded in creating a highly valuable introduction to the subject of applied cryptography. I hope that it can serve as a guide for practitioners to build more secure systems based on cryptography, and as a stepping stone for future researchers to explore the exciting world of cryptography and its applications.

Bart Preneel is a world-renowned cryptographer at the Catholic University of Leuven in Belgium and President of the International Association for Cryptologic Research.