Dive into the secret history of . . . secrets! Cryptology is the art and science of secret communication, and its purpose is to protect precious information and keep people safe. Learn about its building blocks: ciphers, codes, and keys. People have wanted to hide messages and important information for millennia. Read how history's coolest codes and ciphers have progressed from belts and sticks to rotating disks and supercomputers. Use your cryptology skills to design your own secret cipher. And learn about the smart people who built and broke the strongest secret systems.

Publisher Description

This vintage book contains Alexander D’Agapeyeff’s famous 1939 work, Codes and Ciphers - A History of Cryptography. Cryptography is the employment of codes and ciphers to protect secrets, and it has a long and interesting history. This fantastic volume offers a detailed history of cryptography from ancient times to modernity, written by the Russian-born English cryptographer, Alexander D'Agapeyeff. The contents include: - The beginnings of Cryptography - From the Middle Ages Onwards - Signals, Signs, and Secret Languages - Commercial Codes - Military Codes and Ciphers - Types of Codes and Ciphers - Methods of Deciphering Many antiquarian texts such as this, especially those dating back to the 1900s and before, are increasingly hard to come by and expensive, and it is with this in mind that we are republishing this book now in an affordable, modern, high quality edition. It comes complete with a specially commissioned new biography of the author.

"As gripping as a good thriller." --The Washington Post Unpack the science of secrecy and discover the methods behind cryptography--the encoding and decoding of information--in this clear and easy-to-understand young adult adaptation of the national bestseller that's perfect for this age of WikiLeaks, the Sony hack, and other events that reveal the extent to which our technology is never quite as secure as we want to believe. Coders and codebreakers alike will be fascinated by history's most mesmerizing stories of intrigue and cunning--from Julius Caesar and his Caeser cipher to the Allies' use of the Enigma machine to decode German messages during World War II. Accessible, compelling, and timely, The Code Book is sure to make readers see the past--and the future--in a whole new way. "Singh's power of explaining complex ideas is as dazzling as ever." --The Guardian

Join the Cryptokids as they apply basic mathematics to make and break secret codes. This book has many hands-on activities that have been tested in both classrooms and informal settings. Classic coding methods are discussed, such as Caesar, substitution, Vigenère, and multiplicative ciphers as well as the modern RSA. Math topics covered include: - Addition and Subtraction with, negative numbers, decimals, and percentages - Factorization - Modular Arithmetic - Exponentiation - Prime Numbers - Frequency Analysis. The accompanying workbook, The Cryptoclub Workbook: Using Mathematics to Make and Break Secret Codes provides students with problems related to each section to help them master the concepts introduced throughout the book. A PDF version of the workbook is available at no charge on the download tab, a printed workbook is available for $19.95 (K00701). The teacher manual can be requested from the publisher by contacting the Academic Sales Manager, Susie Carlisle

Includes "166 cryptograms."

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

Explains transposition, substitution, and Baconian bilateral ciphers and presents more than one hundred and fifty problems.

Cryptography, the art and science of creating secret codes, and cryptanalysis, the art and science of breaking secret codes, underwent a similar and parallel course during history. Both fields evolved from manual encryption methods and manual codebreaking techniques, to cipher machines and codebreaking machines in the first half of the 20th century, and finally to computerbased encryption and cryptanalysis from the second half of the 20th century. However, despite the advent of modern computing technology, some of the more challenging classical cipher systems and machines have not yet been successfully cryptanalyzed. For others, cryptanalytic methods exist, but only for special and advantageous cases, such as when large amounts of ciphertext are available. Starting from the 1990s, local search metaheuristics such as hill climbing, genetic algorithms, and simulated annealing have been employed, and in some cases, successfully, for the cryptanalysis of several classical ciphers. In most cases, however, results were mixed, and the application of such methods rather limited in their scope and performance. In this work, a robust framework and methodology for the cryptanalysis of classical ciphers using local search metaheuristics, mainly hill climbing and simulated annealing, is described. In an extensive set of case studies conducted as part of this research, this new methodology has been validated and demonstrated as highly effective for the cryptanalysis of several challenging cipher systems and machines, which could not be effectively cryptanalyzed before, and with drastic improvements compared to previously published methods. This work also led to the decipherment of original encrypted messages from WWI, and to the solution, for the first time, of several public cryptographic challenges.