A classical introduction to cryptography - applications for communications security

The book is aimed at bridging the gap between cryptography and its standard applications. From my point of view, it has achieved its goal. This book presents basic tools of cryptography with applications in communication and information security. This book is a compilation of author’s lecture notes that he used for teaching cryptography to undergraduate students. Though this book is titled like any other introductory books on cryptography, this is actually an advanced level textbook covering prehistory of cryptography; symmetric key cryptography; public key cryptography; mathematical topics like algorithmic algebra and number theory for cryptologists and other cryptographic protocols. This book differs significantly from other introductory books, since it covers some topics that other books did not. For example, RSA exponent problem and its equivalence to factorization problem is covered in this book. Also some topics from cryptanalysis of both symmetric and asymmetric primitives are well presented, though it is a book on cryptography. The most important point is that every concept is discussed intuitively with rigorous mathematics. A reader can find how beautiful is cryptography when it joins hand with mathematics. But at the same time too much mathematics will be too boring for some readers and they may find this book difficult to read. This book will answer two questions once it is read. First question is how important is cryptography in todays world and the second question is how fun is cryptography with mathematics. All complexity theory and mathematical preliminaries needed are covered in separate chapters of the book. This means a reader with no mathematical background could directly start reading this book. But a better insight into several discussion points requires additional reading.