Publisher Description

Explains various methods used in cryptography and presents examples to help readers in breaking secret codes

The Secret Code Book is a short introduction to substitution ciphers. The chapters ease young readers into the concept of rotation ciphers and work their way up to the Vigenère cipher. Along the way, readers will also learn about geometric approaches to secret codes such as the Pigpen cipher. As a bonus, there is a brief description of frequency analysis and how it is used to crack secret codes. frper gpbqr obbx In addition, this book actively challenges readers with practice missions where answers are listed in the back. Also, there is a cut-out rotation template that is provided to make your very own cipher disk! After reading this book, you will have all the basic tools needed to create secret messages.

An explanation of the development, methods, and use of cryptography throughout history.

"A cipher is a scheme for creating coded messages for the secure exchange of information. Throughout history, many different coding schemes have been devised. One of the oldest and simplest mathematical systems was used by Julius Caesar. This is where Mathematical Ciphers begins. Building on that simple system, Young moves on to more complicated schemes, ultimately ending with the RSA cipher, which is used to provide security for the Internet. This book is structured differently from most mathematics texts. It does not begin with a mathematical topic, but rather with a cipher. The mathematics is developed as it is needed; the applications motivate the mathematics. As is typical in mathematics textbooks, most chapters end with exercises. Many of these problems are similar to solved examples and are designed to assist the reader in mastering the basic material. A few of the exercises are one-of-a-kind, intended to challenge the interested reader. Implementing encryption schemes is considerably easier with the use of the computer. For all the ciphers introduced in this book, JavaScript programs are available from the Web. In addition to developing various encryption schemes, this book also introduces the reader to number theory. Here, the study of integers and their properties is placed in the exciting and modern context of cryptology. Mathematical Ciphers can be used as a textbook for an introductory course in mathematics for all majors. The only prerequisite is high school mathematics."--Jacket.

Text and illustrations introduce various codes and ciphers and give examples of their use throughout history.

This book is almost entirely concerned with stream ciphers, concentrating on a particular mathematical model for such ciphers which are called additive natural stream ciphers. These ciphers use a natural sequence generator to produce a periodic keystream. Full definitions of these concepts are given in Chapter 2.This book focuses on keystream sequences which can be analysed using number theory. It turns out that a great deal of information can be deducted about the cryptographic properties of many classes of sequences by applying the terminology and theorems of number theory. These connections can be explicitly made by describing three kinds of bridges between stream ciphering problems and number theory problems. A detailed summary of these ideas is given in the introductory Chapter 1.Many results in the book are new, and over seventy percent of these results described in this book are based on recent research results.