Explaining the mathematics of cryptography The Mathematics of Secrets takes readers on a fascinating tour of the mathematics behind cryptography--the science of sending secret messages. Most books about cryptography are organized historically, or around how codes and ciphers have been used, such as in government and military intelligence or bank transactions. Joshua Holden instead shows how mathematical principles underpin the ways that different codes and ciphers operate. Holden focuses on both code making and code breaking and he discusses the majority of ancient and modern ciphers currently known. Holden begins by looking at substitution ciphers, built by substituting one letter or block of letters for another. Explaining one of the simplest and historically well-known ciphers, the Caesar cipher, Holden establishes the key mathematical idea behind the cipher and discusses how to introduce flexibility and additional notation. Holden goes on to explore polyalphabetic substitution ciphers, transposition ciphers, including one developed by the Spartans, connections between ciphers and computer encryption, stream ciphers, and ciphers involving exponentiation. He also examines public-key ciphers, where the methods used to encrypt messages are public knowledge, and yet, intended recipients are still the only ones who are able to read the message. He concludes with a look at the future of ciphers and where cryptography might be headed. Only basic mathematics up to high school algebra is needed to understand and enjoy the book. With a plethora of historical anecdotes and real-world examples, The Mathematics of Secrets reveals the mathematics working stealthily in the science of coded messages.

"The history of war teems with occasions where the interception of dispatches and orders written in plain language has resulted in defeat and disaster for the force whose intentions thus became known at once to the enemy." So begins Colonel Parker Hitt's 1916 Manual for the Solution of Military Ciphers, a foundational text in the history of cryptology. Due largely in part to this manual and Hitt's early cipher inventions, codes became the default communication method for the U.S. military in the twentieth century as codebreakers and cipher machines had proved their worth during World War I. A modified version of Hitt's invention, the M--94 cipher device, was used by the Army for three decades until the Germans decrypted the code during the middle of WWII. To this day, Hitt is known as the "father of American military cryptology." In the first biography of this American hero, historian Betsy Rohaly Smoot brings Hitt's legacy to the fore, chronicling his extraordinary military career and deviation from masculine tropes during the early twentieth century. Smoot reveals that Hitt was a champion for women in the workplace, giving his support to employment of the "Hello Girls," American female telephone operators for the First Army switchboard and working alongside his wife, Genevieve Young Hitt, the first woman to break ciphers for the United States government. Readers of Liza Mundy's Code Girls and David Kahn's The Codebreakers will find an insightful profile of not only an American hero in Parker Hitt's story, but of early military cryptology as well. Drawing from a never-before-seen cache of Hitt's letters, photographs, and diaries, Smoot introduces readers to this unique cryptanalyst's life.

The design of code and cipher systems has undergone major changes in modern times. Powerful personal computers have resulted in an explosion of e-banking, e-commerce and e-mail, and as a consequence the encryption of communications to ensure security has become a matter of public interest and importance. This book describes and analyses many cipher systems ranging from the earliest and elementary to the more recent and sophisticated, such as RSA and DES, as well as wartime machines such as the ENIGMA and Hagelin, and ciphers used by spies. Security issues and possible methods of attack are discussed and illustrated by examples. The design of many systems involves advanced mathematical concepts and this is explained in detail in a major appendix. This book will appeal to anyone interested in codes and ciphers as used by private individuals, spies, governments and industry throughout history.

This text tells the full story of the Comanche Code Talkers. Drawing on interviews with all surviving members of the unit, their original training officer, and fellow soldiers, as well as military records and news accounts, William C. Meadows follows the group from their recruitment and training to their active duty in World War II and on through their postwar lives up to the present. He also provides a comparison of Native American code talking programs, comparing the Comanche Code Talkers with their better-known Navajo counterparts in the Pacific and with other Native Americans who used their languages, coded or not, for secret communication. Meadows sets this history in a larger discussion of the development of Native American code talking in World Wars I and II, identifying two distinct forms of Native American code talking, examining the attitudes of the American military toward Native American code talkers, and assessing the complex cultural factors that led Comanche and other Native Americans to serve their country in this way.

The dramatic, untold story of the brilliant team whose feats of innovation and engineering created the world's first digital electronic computer--decrypting the Nazis' toughest code, helping bring an end to WWII, and ushering in the information age. Planning the invasion of Normandy, the Allies knew that decoding the communications of the Nazi high command was imperative for its success. But standing in their way was an encryption machine they called Tunny (British English for "tuna"), which was vastly more difficult to crack than the infamous Enigma cipher.   To surmount this seemingly impossible challenge, Alan Turing, the Enigma codebreaker, brought in a maverick English working-class engineer named Tommy Flowers who devised the ingenious, daring, and controversial plan to build a machine that would calculate at breathtaking speed and break the code in nearly real time. Together with the pioneering mathematician Max Newman, Flowers and his team produced--against the odds, the clock, and a resistant leadership--Colossus, the world's first digital electronic computer, the machine that would help bring the war to an end.   Drawing upon recently declassified sources, David A. Price's Geniuses at War tells, for the first time, the full mesmerizing story of the great minds behind Colossus and chronicles the remarkable feats of engineering genius that marked the dawn of the digital age.

The award-winning New York Times bestseller about the American women who secretly served as codebreakers during World War II--a "prodigiously researched and engrossing" (New York Times) book that "shines a light on a hidden chapter of American history" (Denver Post). Recruited by the U.S. Army and Navy from small towns and elite colleges, more than ten thousand women served as codebreakers during World War II. While their brothers and boyfriends took up arms, these women moved to Washington and learned the meticulous work of code-breaking. Their efforts shortened the war, saved countless lives, and gave them access to careers previously denied to them. A strict vow of secrecy nearly erased their efforts from history; now, through dazzling research and interviews with surviving code girls, bestselling author Liza Mundy brings to life this riveting and vital story of American courage, service, and scientific accomplishment.

Cryptography is now ubiquitous - moving beyond the traditional environments, such as government communications and banking systems, we see cryptographic techniques realized in Web browsers, e-mail programs, cell phones, manufacturing systems, embedded software, smart buildings, cars, and even medical implants. Today's designers need a comprehensive understanding of applied cryptography.

This is the first biography of Capt. Joe Rochefort, the Officer in Charge of Station Hypo the U.S. Navy's decrypt unit at Pearl Harbor and his key role in breaking the Imperial Japanese Navy's main code before the Battle of Midway. It brings together the disparate threads of Rochefort's life and career, beginning with his enlistment in the Naval Reserve in 1918 at age 17 (dropping out of high school and adding a year to his age). It chronicles his earliest days as a mustang (an officer who has risen from the ranks), his fortuitous posting to Washington, where he headed the Navy's codebreaking desk at age 25, then, in another unexpected twist, found himself assigned to Tokyo to learn Japanese. This biography records Rochefort's surprising love-hate relationship with cryptanalysis, his joyful exit from the field, his love of sea duty, his adventure-filled years in the '30s as the right-hand man to the Commander in Chief, U.S. Fleet, and his reluctant return to codebreaking in mid-1941 when he was ordered to head the Navy's decrypt unit at Pearl (Station Hypo).

This book reveals the historical context and the evolution of the technically complex Allied Signals Intelligence (Sigint) activity against Japan from 1920 to 1945. It traces the all-important genesis and development of the cryptanalytic techniques used to break the main Japanese Navy code (JN-25) and the Japanese Army's Water Transport Code during WWII. This is the first book to describe, explain and analyze the code breaking techniques developed and used to provide this intelligence, thus closing the sole remaining gap in the published accounts of the Pacific War. The authors also explore the organization of cryptographic teams and issues of security, censorship, and leaks. Correcting gaps in previous research, this book illustrates how Sigint remained crucial to Allied planning throughout the war. It helped direct the advance to the Philippines from New Guinea, the sea battles and the submarine onslaught on merchant shipping. Written by well-known authorities on the history of cryptography and mathematics, Code Breaking in the Pacific is designed for cryptologists, mathematicians and researchers working in communications security. Advanced-level students interested in cryptology, the history of the Pacific War, mathematics or the history of computing will also find this book a valuable resource.