A broad introduction to cryptography—what it is, how it really works, what its future holds, and why every informed citizen should understand its basics.
We all keep secrets—from our gym locker codes to our email passwords to our online interactions. And we choose to share those secrets only with those whom we trust. So, too, do organizations, businesses, governments, and armies. In this fascinating book Cryptography, Panos Louridas provides a broad and accessible introduction to cryptography, the art and science of keeping and revealing secrets. Louridas explains just how cryptography works to keep our communications confidential, tracing it back all the way to its ancient roots. Then he follows its long and winding path to where we are today and reads the signs that point to where it may go tomorrow.
A few years back, interest in cryptography was restricted to specialists. Today, as we all live our lives attuned to our digital footprint and the privacy issues it entails, it becomes more and more essential to have a basic understanding of cryptography and its applications to everyday life. Starting with classical cryptography, Cryptography takes the reader all the way up to the twenty-first century cryptographic applications that underpin our lives in the digital realm. Along the way, Louridas also explains concepts such as symmetric cryptography, asymmetric cryptography, cryptographic protocols and applications, and finally, quantum and post-Quantum cryptography as well as the links between cryptography and computer security.
This book is an introduction to cryptography, the art and science of keeping and revealing secrets. That is a blithe definition, but we have enough pages ahead of us to flesh it out. Cryptography is ancient, and the methods of cryptography have changed over the centuries and are changing the moment these lines are being written. As we’ll see, what cryptographers were doing in earlier times bears scant resemblance to what cryptographers are doing today. To understand their craft, we will have to visit the past, follow the path to where we are now, and see the signs pointing to where we may go tomorrow.
Anything that has been evolving for a long time must adapt to remain relevant. Cryptography is no exception. From an endeavor akin to puzzle solving, it has progressed to an amalgamation of solid mathematical foundations and lots of clever engineering. In the past, cryptography could be a gentleman’s pastime. Now it is the playground of mathematicians, programmers, and computer engineers.
That presents us with a challenge. This is a book that aims to give the reader a wide understanding of cryptography. It is not just a history of cryptography and its applications, although we will go through its evolution in order to understand where we are today. But to really understand cryptography, it is necessary not only to know who did what when but also to understand how cryptography actually works. Modern cryptography is far more technical than cryptographic methods of the past, but should not be hand-waved into facile explanations. That would be a slight both to all the people who have worked hard to make cryptography what it is today and to the readers who deserve a better treatment of a subject that impacts in multiple ways their everyday lives.
Preface 1 Classical Cryptography 2 Symmetric Cryptography 3 Key Exchange and Public Key Cryptography 4 Protocols and Applications 5 A Saucerful of Secrets Epilogue