Derek Taunt, Alan Stripp and Donald Davies kindly explained to me how Bletchley Park broke Enigma, and I was also helped by the Bletchley Park Trust, whose members regularly give enlightening lectures on a variety of topics. Dr. Mohammed Mrayati and Dr. Ibrahim Kadi have been involved in revealing some of the early breakthroughs in Arab cryptanalysis, and were kind enough to send me relevant documents. The periodical
Cryptologia
also carried articles about Arabian cryptanalysis, as well as many other cryptographic subjects, and I would like to thank Brian Winkel for sending me back issues of the magazines.
I would encourage readers to visit the National Cryptologic Museum near Washington, D.C. and the Cabinet War Rooms in London, and I hope that you will be as fascinated as I was during my visits. Thank you to the curators and librarians of these museums for helping me with my research. When I was pressed for time, James Howard, Bindu Mathur, Pretty Sagoo, Anna Singh and Nick Shearing all helped me to uncover important and interesting articles, books and documents, and I am grateful to them for their efforts. Thanks also go to Antony Buonomo at
www.vertigo.co.uk
who helped me to establish my Web site.
As well as interviewing experts, I have also depended on numerous books and articles. The list of further reading contains some of my sources, but it is neither a complete bibliography nor a definitive reference list. Instead, it merely includes material that may be of interest to the general reader. Of all the books I have come across during my research, I would like to single out one in particular:
The Codebreakers
by David Kahn. This book documents almost every cryptographic episode in history, and as such it is an invaluable resource.
Various libraries, institutions and individuals have provided me with photographs. All the sources are listed in the picture credits, but particular thanks go to Sally McClain, for sending me photographs of the Navajo code talkers; Professor Eva Brann, for discovering the only known photo of Alice Kober; Joan Chadwick, for sending me a photo of John Chadwick; and Brenda Ellis, for allowing me to borrow photos of James Ellis. Thanks also go to Hugh Whitemore, who gave me permission to use a quote from his play
Breaking the Code
, based on Andrew Hodges’ book
Alan Turing-The Enigma
.
On a personal note, I would like to thank friends and family who put up with me over the two years while I was writing this book. Neil Boynton, Dawn Dzedzy, Sonya Holbraad, Tim Johnson, Richard Singh and Andrew Thompson all helped me to keep sane while I was struggling with convoluted cryptographic concepts. In particular, Bernadette Alves supplied me with a rich mixture of moral support and perceptive criticism. Traveling back in time, thanks also go to all the people and institutions that have shaped my career, including Wellington School, Imperial College and the High Energy Physics Group at Cambridge University; Dana Purvis, at the BBC, who gave me my first break in television; and Roger Highfield, at the
Daily Telegraph
, who encouraged me to write my first article.
Finally, I have had the enormous good fortune to work with some of the best people in publishing. Patrick Walsh is an agent with a love of science, a concern for his authors and a boundless enthusiasm. He has put me in touch with the kindest and most capable publishers, most notably Fourth Estate, whose staff endure my constant stream of queries with great spirit. Last, but certainly not least, my editors, Christopher Potter, Leo Hollis and Peternelle van Arsdale, have helped me to steer a clear path through a subject that twists and turns its way across three thousand years. For that I am tremendously grateful.
Further Reading
The following is a list of books aimed at the general reader. I have avoided giving more detailed technical references, but several of the texts listed contain a detailed bibliography. For example, if you would like to know more about the decipherment of Linear B (
Chapter 5
), then I would recommend
The Decipherment of Linear B
by John Chadwick. However, if this book is not detailed enough, then please refer to the references it contains.
There is a great deal of interesting material on the Internet relating to codes and ciphers. In addition to the books, I have therefore listed a few of the Web sites that are worth visiting.
General
Kahn, David,
The Codebreakers
(New York: Scribner, 1996).
A 1,200-page history of ciphers. The definitive story of cryptography up until the 1950s.
Newton, David E.,
Encyclopedia of Cryptology
(Santa Barbara, CA: ABC-Clio, 1997).
A useful reference, with clear, concise explanations of most aspects of ancient and modern cryptology.
Smith, Lawrence Dwight,
Cryptography
(New York: Dover, 1943).
An excellent elementary introduction to cryptography, with more than 150 problems. Dover publishes many books on the subject of codes and ciphers.
Beutelspacher, Albrecht,
Cryptology
(Washington, D.C.: Mathematical Association of America, 1994).
An excellent overview of the subject, from the Caesar cipher to public key cryptography, concentrating on the mathematics rather than the history. It is also the cryptography book with the best subtitle: An Introduction to the Art and Science of Enciphering, Encrypting, Concealing, Hiding, and Safeguarding, Described Without any Arcane Skullduggery but not Without Cunning Waggery for the Delectation and Instruction of the General Public
.
Chapter 1
Gaines, Helen Fouché,
Cryptanalysis
(New York: Dover, 1956).
A study of ciphers and their solution. An excellent introduction to cryptanalysis, with many useful frequency tables in the appendix.
Al-Kadi, Ibraham A., “The origins of cryptology: The Arab contributions,”
Cryptologia
, vol. 16, no. 2 (April 1992), pp. 97–126.
A discussion of recently discovered Arab manuscripts, and the work of al-Kindī.
Fraser, Lady Antonia,
Mary Queen of Scots
(London: Random House, 1989).
A highly readable account of the life of Mary Queen of Scots.
Smith, Alan Gordon,
The Babington Plot
(London: Macmillan, 1936).
Written in two parts, this book examines the plot from the points of view of both Babington and Walsingham.
Steuart, A. Francis (ed.),
Trial of Mary Queen of Scots
(London: William Hodge, 1951).
Part of the Notable British Trials series.
Chapter 2
Standage, Tom,
The Victorian Internet
(London: Weidenfeld & Nicolson, 1998). The remarkable story of the development of the electric telegraph.
Franksen, Ole Immanuel,
Mr Babbage’s Secret
(London: Prentice-Hall, 1985). Contains a discussion of Babbage’s work on breaking the Vigenère cipher.
Franksen, Ole Immanuel, “Babbage and cryptography. Or, the mystery of Admiral Beaufort’s cipher,”
Mathematics and Computer Simulation
, vol. 35, 1993, pp. 327–67.
A detailed paper on Babbage’s cryptological work, and his relationship with Rear Admiral Sir Francis Beaufort.
Rosenheim, Shawn,
The Cryptographic Imagination
(Baltimore, MD: Johns Hopkins University Press, 1997).
An academic assessment of the cryptographic writings of Edgar Allan Poe and their influence on literature and cryptography.
Poe, Edgar Allan,
The Complete Tales and Poems of Edgar Allan Poe
(London: Penguin, 1982).
Includes “The Gold Bug.”
Viemeister, Peter,
The Beale Treasure: History of a Mystery
(Bedford, VA: Hamilton’s, 1997).
An in-depth account of the Beale ciphers written by a respected local historian. It includes the entire text of the Beale pamphlet, and is most easily obtained directly from the publishers; Hamilton’s, P.O. Box 932, Bedford, VA, 24523, USA.
Chapter 3
Tuchman, Barbara W.,
The Zimmermann Telegram
(New York: Ballantine, 1994). A highly readable account of the most influential decipherment in the First World War.
Yardley, Herbert O.,
The American Black Chamber
(Laguna Hills, CA: Aegean Park Press, 1931).
A racy history of cryptography, which was a controversial best-seller when it was first published.
Chapter 4
Hinsley, F.H., British Intelligence in the Second World War: Its Influence on Strategy and Operations (London: HMSO, 1975)
.
The authoritative record of intelligence in the Second World War, including the role of Ultra intelligence.
Hodges, Andrew,
Alan Turing: The Enigma
(London: Vintage, 1992). The life and work of Alan Turing. One of the best scientific biographies ever written.
Kahn, David,
Seizing the Enigma
(London: Arrow, 1996).
Kahn’s history of the Battle of the Atlantic and the importance of cryptography. In particular, he dramatically describes the “pinches” from U-boats which helped the codebreakers at Bletchley Park.
Hinsley, F.H., and Stripp, Alan (eds),
The Codebreakers: The Inside Story of Bletchley Park
(Oxford: Oxford University Press, 1992).
A collection of illuminating essays by the men and women who were part of one of the greatest cryptanalytic achievements in history.
Smith, Michael,
Station X
(London: Channel 4 Books, 1999).
The book based on the British Channel 4 TV series of the same name, containing anecdotes from those who worked at Bletchley Park, otherwise known as Station X.
Harris, Robert,
Enigma
(London: Arrow, 1996).
A novel revolving around the codebreakers at Bletchley Park.
Chapter 5
Paul, Doris A.,
The Navajo Code Talkers
(Pittsburgh, PA: Dorrance, 1973).
A book devoted to ensuring that the contribution of the Navajo code talkers is not forgotten.
McClain, S.,
The Navajo Weapon
(Boulder, CO: Books Beyond Borders, 1994).
A gripping account that covers the entire story, written by a woman who has spent much time talking to the men who developed and used the Navajo code.
Pope, Maurice,
The Story of Decipherment
(London: Thames & Hudson, 1975).
A description of various decipherments, from Hittite hieroglyphs to the Ugaritic alphabet, aimed at the layperson.
Davies, W.V.,
Reading the Past: Egyptian Hieroglyphs
(London: British Museum Press, 1997).
Part of an excellent series of introductory texts published by the British Museum. Other authors in the series have written books on cuneiform, Etruscan, Greek inscriptions, Linear B, Maya glyphs, and runes.
Chadwick, John,
The Decipherment of Linear B
(Cambridge: Cambridge University Press, 1987).
A brilliant description of the decipherment.
Chapter 6
Data Encryption Standard
, FIPS Pub. 46–1 (Washington, D.C.: National Bureau of Standards, 1987).
The official DES document.
Diffie, Whitfield, and Hellman, Martin, “New directions in cryptography,”
IEEE Transactions on Information Theory
, vol. IT-22 (November 1976), pp. 644–54.
The classic paper that revealed Diffie and Hellman’s discovery of key exchange, opening the door to public key cryptography.
Gardner, Martin, “A new kind of cipher that would take millions of years to break,”
Scientific American
, vol. 237 (August 1977), pp. 120–24.
The article which introduced RSA to the world.
Hellman, M.E., “The mathematics of public key cryptography,”
Scientific American
, vol. 241 (August 1979), pp. 130–39.
An excellent overview of the various forms of public key cryptography. Schneier, Bruce,
Applied Cryptography
(New York: John Wiley & Sons, 1996)
An excellent survey of modern cryptography. A definitive, comprehensive, and authoritative introduction to the subject.
Chapter 7
Zimmermann, Philip R.,
The Official PGP User’s Guide
(Cambridge, MA: MIT Press, 1996).
A friendly overview of PGP, written by the man who developed it.
Garfinkel, Simson,
PGP: Pretty Good Privacy
(Sebastopol, CA: O’Reilly & Associates, 1995).
An excellent introduction to PGP and the issues surrounding modern cryptography.
Bamford, James,
The Puzzle Palace
(London: Penguin, 1983).
Inside the National Security Agency, America’s most secret intelligence organization.
Koops, Bert-Jaap,
The Crypto Controversy
(Boston, MA: Kluwer, 1998).
An excellent survey of the impact of cryptography on privacy, civil liberty, law enforcement and commerce.
Diffie, Whitfield, and Landau, Susan,
Privacy on the Line
(Cambridge, MA: MIT Press, 1998).
The politics of wiretapping and encryption.
Chapter 8
Deutsch, David,
The Fabric of Reality
(London: Allen Lane, 1997).
Deutsch devotes one chapter to quantum computers, in his attempt to combine quantum physics with the theories of knowledge, computation and evolution.
Bennett, C. H., Brassard, C., and Ekert, A., “Quantum Cryptography,”
Scientific American
, vol. 269 (October 1992), pp. 26–33.
A clear explanation of the evolution of quantum cryptography.