Cryptologic History Research Articles

David Kahn, in remembrance: an INS special forum

ABSTRACT David Kahn was one of America’s leading experts on the history of cryptology, the art and science of breaking the communications codes, ciphers, and secret writing of hostile nations and terrorist organizations – a vital intelligence tradecraft for anticipating potentially dangerous operations of foreign adversaries. As both a journalist and a professional historian, he pursued scholarly interests in cryptology as well as modern German history. His most well-known book, entitled The Codebreakers, influenced the field of cryptology and attracted many young readers to this intelligence profession. Kahn wrote many other studies on the topic and founded the journal Cryptologia. He received an array of honors for his work, including induction into the National Security Agency’s Cryptologic Hall of Fame. In addition, Kahn was a popular social fixture at prestigious clubs in New York City and a member of several boards of editors devoted to Intelligence Studies, including this journal.

Cryptologic History Symposium, May 8–10, 2024

Cryptologic History Symposium, May 8–10, 2024

The Codebreakers war: David Kahn, Macmillan, the government, and the making of a cryptologic history masterpiece

David Kahn’s The Codebreakers, published in 1967, is the first modern comprehensive history of cryptology. Based on extensive research, including interviews with former government cryptologists in the United States and Europe, Kahn’s volume blazed a trail that numerous historians would follow. It also attracted the attention of intelligence officials in Washington and London, who sought to excise or edit passages in the book. In one of these, Kahn made but agreed to remove a claim that during World War II the Allies had broken the supposedly invulnerable Enigma, a feat that would remain secret until the following decade.

Sources and methods for cryptologic history: researching individuals (and the biography boom)

Recent years have seen a surge in interest in writing (and reading) biographies of renowned cryptologists. This article looks at the surge and provides suggestions for those wishing to research and write both short form and long form biographies and those who wish to know more about a cryptologist in their family.

18th cryptologic history symposium

18th cryptologic history symposium

Sources and methods: uncovering the story of American Cryptology in World War I

This article discusses source material for studying US cryptologic efforts during World War I. Much of this material was used to prepare the forthcoming publication from NSA’s Center for Cryptologic History, From the Ground Up: American Cryptology During World War I. The author suggests areas for additional scholarship in the field.

Sources and methods: contingency and its role in researching records of cryptologic history - a discussion and some lessons to apply for future research

Elusive as contingent discoveries of cryptologic records might appear to researchers, it is not a phenomenon hostage to “pure luck”. These two essays – on the discovery of diplomatic translations relating to the Nazi Gold controversy and the uncovering of hitherto “lost” records of the career and contributions to early American cryptology by Parker Hitt – illustrate how contingent finds are more a product of research techniques and a dogged attitude on the part of the individual.

Sources and methods for cryptologic history: NSA.gov - a tour through its history and resources

In 2020, the National Security Agency will celebrate 25 years of its presence on the World Wide Web at www.NSA.gov. This article will provide a brief history of its development and evolution, paying special attention to the thousands of declassified historic records which are important resources for researchers of cryptologic history.

Sources and methods for cryptologic history: the William and Elizebeth Smith Friedman collections

This article, the third in a series of columns devoted to sources and methods for cryptologic history, profiles the William and Elizebeth Smith Friedman Collections at the George C. Marshall Research Library. After providing an overview of how the Friedmans assembled their collections, the article details their scope and organization and notes the inventories, guides, and finding aids that they and others have compiled over the years. A number of digitized documents are identified, as are other notable items in each collection. A final section offers brief description of other sources of information about the Friedmans.

Sources and methods for cryptologic history: Research at the US National Archives–the “Big Two” Record Groups

This is the second in a series of columns devoted to sources and methods for cryptologic history. The focus of the series is on primary sources and repositories. We begin with a look at the two major record groups pertaining to cryptology at the US National Archives – Record Group 457, the records of the National Security Agency, and Record Group 38, the records of the Chief of Naval Operations.

Introducing a new Cryptologia series: Sources and methods for cryptologic history

The idea for a regular column in Cryptologia devoted to a discussion of sources and methods came from recurring discussion among the three of us about the future of cryptologic history and a desire to encourage others to do research and writing in the field. We are all retired from the National Security Agency (two of us from the Center for Cryptologic History (CCH) and one from the Office of Strategy, Policy, and Plans). Each of us continues to research and write on cryptologic subjects. This article summarizes our sense of the state of the field and outlines the topics for future articles in this series.

Evolución de los sistemas criptográficos desde la Edad Media a la Moderna

This article tries to describe the history of cryptology from Ancient to Early Modern times, paying special attention to the emerging of polyalphabetic ciphers. The author discusses three main reasons for this fast evolution of ideas in Early Modern Europe: the final implementation of the paper, the appearance of postal services and the beginning of modern diplomacy. The text concludes with an observation concerning the curious discrepancy between the actual use of ciphers and the evolution of new cryptologic technologies.

Mathematics in the History of Cryptography

For eight years, the author has taught a course in cryptology for undergraduate non-mathematics majors [15]. However, has his approach to the course been appropriate or has he, along with many others, been doing the history of cryptology an injustice? In this article, the author examines how some textbook authors and mathematicians have approached the connection between math and cryptology. He will look at why people make the connections they do and how they can do better.

A brief history of cryptology and cryptographic algorithms

The science of cryptology is made up of two halves. Cryptography is the study of how to create secure systems for communications. Cryptanalysis is the study of how to break those systems. The conflict between these two halves of cryptology is the story of secret writing. For over 2,000 years, the desire to communicate securely and secretly has resulted in the creation of numerous and increasingly complicated systems to protect one's messages. Yet for every system there is a cryptanalyst creating a new technique to break that system. With the advent of computers the cryptographer seems to finally have the upper hand. New mathematically based cryptographic algorithms that use computers for encryption and decryption are so secure that brute-force techniques seem to be the only way to break them so far. This work traces the history of the conflict between cryptographer and cryptanalyst, explores in some depth the algorithms created to protect messages, and suggests where the field is going in the future.

Secret history: the story of cryptology

Most available cryptology books primarily focus on either mathematics or history. Breaking this mold, Secret History: The Story of Cryptology gives a thorough yet accessible treatment of both the mathematics and history of cryptology. Requiring minimal mathematical prerequisites, the book presents the mathematics in sufficient detail and weaves the history throughout the chapters. In addition to the fascinating historical and political sides of cryptology, the authora former Scholar-in-Residence at the U.S. National Security Agency (NSA) Center for Cryptologic Historyincludes interesting instances of codes and ciphers in crime, literature, music, and art. Following a mainly chronological development of concepts, the book focuses on classical cryptology in the first part. It covers Greek and Viking cryptography, the Vigenre cipher, the one-time pad, transposition ciphers, Jeffersons cipher wheel, the Playfair cipher, ADFGX, matrix encryption, World War II cipher systems (including a detailed examination of Enigma), and many other classical methods introduced before World War II. The second part of the book examines modern cryptology. The author looks at the work of Claude Shannon and the origin and current status of the NSA, including some of its Suite B algorithms such as elliptic curve cryptography and the Advanced Encryption Standard. He also details the controversy that surrounded the Data Encryption Standard and the early years of public key cryptography. The book not only provides the how-to of the Diffie-Hellman key exchange and RSA algorithm, but also covers many attacks on the latter. Additionally, it discusses Elgamal, digital signatures, PGP, and stream ciphers and explores future directions such as quantum cryptography and DNA computing. With numerous real-world examples and extensive references, this book skillfully balances the historical aspects of cryptology with its mathematical details. It provides readers with a sound foundation in this dynamic field.

Announcement of the 2013 Cryptologic History Symposium “Technological Change and Cryptology: Meeting the Historical Challenges” 17–18 October 2013

The National Security Agency's Center for Cryptologic History biennial Cryptologic History Symposium is scheduled for Thursday and Friday, 17–18 October 2013. The theme of the Symposium is “Technol...

1929–1931: A Transition Period in U.S. Cryptologic History

The years 1929 through 1931 were among the most turbulent in American cryptology. During this period, the joint War and State Department Cipher Bureau of Herbert Yardley was closed. The Army created the Signal Intelligence Service under William Friedman. Finally, the Army and Navy began their first tentative steps towards inter-service cooperation. This article examines these events in detail and also takes a look at the relationship between Yardley and Friedman.

Review of the 2011 Cryptologic History Symposium Cryptology in War and Peace: Crisis Points in History

As this review is being written, the 2011 Cryptologic History Symposium has just ended. This biennial gathering, which took place on Thursday and Friday, November 6 and 7, was a gathering of “Histo...

What's the Use of Cryptologic History?

Continued secrecy surrounding signals intelligence during the Cold War has profoundly distorted the historical record, making a full and accurate military, diplomatic, and presidential history of the last half century impossible for now. Not only history, but the ongoing intelligence enterprise itself, would be better served by significantly greater openness. This article is adapted from the Schorreck Memorial Lecture in Cryptologic History, presented by the author at the National Cryptologic Museum, Ft. Meade, Maryland, 24 May 2010, and the National Security Agency, 26 May 2010.

Review of the 2009 Cryptologic History Symposium: Global Perspectives on Cryptologic History

Cryptologia readers should mark on their calendars and plan to participate in the Cryptologic History Symposium scheduled for October 2011. The 2009 Symposium has just ended, and it was a wonderful...