Second Edition

with a foreword by Ron Rivest

Heavily revised and updated, the long-awaited second edition of Understanding Cryptography follows the unique approach of making modern cryptography accessible to a broad audience, requiring only a minimum of prior knowledge.

This must-have book is indispensable as a textbook for graduate and advanced undergraduate courses, as well as for self-study by designers and engineers.

About the Book

Understanding and employing cryptography has become a central requirement for securing virtually any digital application, whether user app, cloud service, or even medical implant.

After introducing basic cryptography concepts, this seminal textbook covers nearly all symmetric, asymmetric, and post-quantum cryptographic algorithms currently in use in applications — ranging from cloud computing and smart phones all the way to industrial systems, block chains, and cryptocurrencies.

Topics and features

  • Helps develop a comprehensive understanding of modern applied cryptography
  • Provides a thorough introduction to post-quantum cryptography consisting of the three standardized cipher families
  • Includes for every chapter a comprehensive problem set, extensive examples, and a further-reading discussion
  • Communicates, using a unique pedagogical approach, the essentials about foundations and use in practice, while keeping mathematics to a minimum
  • Supplies up-to-date security parameters for all cryptographic algorithms
  • Incorporates chapter reviews and discussion on such topics as historical and societal context

Ron Rivest

(Cryptographer, Institute Professor at MIT and one of the inventors of the RSA algorithm)

“[…] I recommend this book highly for both undergraduate and graduate classroom use; it can easily be augmented for students with a more theoretical orientation. This book is also recommended for self-study, for anyone who wishes to bring themselves up-to-date on where this exciting field is going.

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About us

The authors have more than 20 years’ experience teaching cryptography at various universities in the US and Europe. In addition to being renowned scientists, they have extensive experience with applying cryptography in industry, from which they have drawn important lessons for their teaching.

Christof Paar

Founding director at the Max Planck Institute for Security and Privacy in Bochum, Germany and affiliated professor at the University of Massachusetts Amherst

Prior to joining the MPI, Christof was with the Ruhr University Bochum (2001-2019) and WPI in Massachusetts (1995-2001). He spent the academic years 2008/09 and 2014 – 2016 as a research professor at UMass Amherst. He received a Ph.D. in engineering from the Institute for Experimental Mathematics at the University of Essen in 1994.

His research lies in the area of embedded security. His group is currently working on hardware Trojans, technical and cognitive aspects of (hardware) reverse engineering, physical layer security and the security of cyber-physical systems. He is one of the spokespersons of the Excellence Cluster CASA – Cyber Security in the Age of Large-Scale Adversaries.

Jan Pelzl

Professor for Computer Security at the Applied University of Hamm-Lippstadt, Germany and independent IT-Security Consultant

Before becoming a Professor, he was Managing Director of ESCRYPT – Embedded Security, a leading security consultancy company. He has successfully managed numerous national and international industry projects, and has a deep insight into security needs in the real world.

As a researcher, Dr. Pelzl had investigated practical aspects of elliptic curve-based cryptography and cryptanalysis. He has published extensively about his theoretical and industrial work at leading international conferences and journals. Dr. Pelzl holds a Ph.D. in applied cryptography from the Ruhr University Bochum. He is independent consultant for industrial security for many years and focusses on security in automation and embedded systems.

Tim Güneysu

Pro­fes­sor at the Chair for Se­cu­ri­ty En­gi­nee­ring at the Ruhr Uni­ver­si­ty Bo­chum, Germany and Pro­fes­sor/Se­ni­or Re­se­ar­cher at the Ger­man Re­se­arch Cen­ter for Ar­ti­fi­ci­al In­tel­li­gence (DFKI)

Tim received a PhD in Elec­tri­cal En­gi­nee­ring and In­for­ma­ti­on Tech­no­lo­gy from the Ruhr Uni­ver­si­ty Bo­chum in 2009. From 2011 – 2015 he was As­sis­tent Pro­fes­sor of the Hard­ware Se­cu­ri­ty Group in Bochum and spent Aug 2015 – Jul 2017 as As­so­cia­te Pro­fes­sor for Com­pu­ter En­gi­nee­ring and IT-Se­cu­ri­ty at theUni­ver­si­ty of Bre­men

Tim’s primary research topics are in the secure design and implementation of (embedded) systems, including aspects such as long-term secure cryptographic implementation, the design of security layers/architectures and related aspects of hardware-based security. Tim published and contributed to more than 95 peer-reviewed journal and conference publications in the area of applied security and cryptography.

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Reviews (First Edition)

Dont’t take our word for it – here’s what some of our readers say:

[…] Mainly targeting undergraduate students, the book gives a good understandable introduction to cryptography. Most importantly, this book does not make any assumptions on prior knowledge in neither mathematics nor computer science. It is therefore not only suited for undergraduate students in mathematics or in the computer science field, but rather also for students from other domains requiring crypto skills such as legal people for example.
[…] Its strength is really its ability to explain the complex content in an easy understandable but yet accurate manner.
[…] It is really hard to find negativ points or disadvantages of the present book.

Luigi Lo Iacono

European University of Applied Sciences, on

I came across this book on accident; I was googling around for articles by Preneel and found this book, in which he wrote the foreword. Frankly, I hope this book eventually replaces most, if not all of the mainstream texts on cryptography. My only complaint about this book is that I no longer feel like one of the rare geniuses that thoroughly and completely understands cryptography. Thanks to this book, any dummy off the street can understand cryptography nearly as well as I do and they do not need a computer science or math degree. No prerequisite knowledge is required, other than the ability to read but there is plenty of math if you want to study it. […]

Mike G.


I used the book “Understanding Cryptography” as text book for a basic course in cryptography. It is execellent structured, compact and clearly written and reaches the goal to be “Understandable”. It offers a basic course, but it opens many possibilities to deepen the content and to explain the mathematical background. It fills a gap of well known cryptographic bestsellers, which are too detailled for a basic course. It is suitable also for engineers and students, who want to learn actual cryptography by self study. It contains the cryptographic mechanisms and algorithms, which are (or should be) used today (2010), for example presenting Elliptic Curve Cryptography not as an exotic cryptography, but as state of the art. Thanks to the authors, also for the well designed exercises.

Christoph Ruland

University of Siegen, Germany, on