The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet by David Kahn

The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet Reviews

• 
  ☘Misericordia☘ ⚡ϟ⚡⛈⚡☁ ❇️❤❣

  Q: ...Zimmermann telegram...
  It would not require much wit for the Americans to surmise that England might also be supervising the code telegrams of another neutral: the United States, which, like Sweden, was working as a messenger boy for the Germans and had, in fact, transmitted this very message. This realization would both embarrass and anger the United States and would not conduce to pro-Allied feelings. ...
  Suddenly, Americans in the middle of the continent who could not get excited about the distant poppings of a European war jerked awake in the realization that the war was at their border. Texans blinked in astonishment: the Germans meant to give away their state! The Midwest, unmoved because untouched by the submarine issue, imagined a German-officered army crossing the Rio Grande and swung over to the side of the Allies. The Far West blew up like a land mine at the mention of Japan ...
  And so it came about that Room 40’s solution of an enemy message helped propel the United States into the First World War, enabling the Allies to win, and into world leadership, with all that that has entailed. No other single cryptanalysis has had such enormous consequences. Never before or since has so much turned upon the solution of a secret message. For those few moments in time, the codebreakers held history in the palm of their hand. (c)
  Q:
  This kind of work, particularly in the early stages of a difficult cryptanalysis, is perhaps the most excruciating, exasperating, agonizing mental process known to man. (c)
  Q:
  since military operations are usually accompanied by an increase in communications, traffic analysis can infer the imminence of such operations by watching the volume of traffic. When combined with direction-finding, it can often approximate the where and when of a planned movement. (c)
  Q:
  The solution had taken a terrific toll. The restless turning of the mind tormented by a puzzle, the preoccupation at meals, the insomnia, the sudden wakening at midnight, the pressure to succeed because failure could have national consequences, the despair of the long weeks when the problem seemed insoluble, the repeated dashings of uplifted hopes, the mental shocks, the tension and the frustration and the urgency and the secrecy all converged and hammered furiously upon his skull. (c)
  Q:
  the use of atbash in the Bible sensitized the monks and scribes of the Middle Ages to the idea of letter substitution. And from them flowed the modern use of ciphers—as distinct from codes—as a means of secret communication. (c)
  Q:
  The secret police... It gathers external intelligence as well as guarding internal security. It thus encompasses the functions of a C.I.A. as well as an F.B.I. This seemingly unusual situation began under the czars, when revolutionary agents were very numerous outside Russia. (c)
  Q:
  Yardley nearly suffered a nervous breakdown, and in February went to Arizona for four months to recover his health. Several of his assistants had already had trouble in this regard. One babbled incoherently; a girl dreamed of chasing around the bedroom a bulldog that, when caught, had “code” written on its side; another could lighten the enormous sack of pebbles that she carried in a recurring nightmare only by finding a stone along a lonely beach that exactly matched one of her pebbles, which she could then cast into the sea. All three resigned. (c)
  Q:
  This cipher is absolutely undecipherable. (c)
  Q:
  One letter containing knitting instructions was held up long enough for an examiner to knit a sweater to see if the given sequence of knit two and cast off contained a hidden message like that of Madame Defarge, who knitted into her “shrouds” the names of further enemies of the French Republic, “whose lives the guillotine then surely swallowed up.” A stamp bank was maintained at each censorship station; examiners removed loose stamps, which might spell out a code message, and replaced them with others of equal value, but of different number and denomination. Blank paper, often sent from the United States to relatives in paper-short countries, was similarly replaced from a paper bank to obviate secret-ink transmissions. Childish scrawls, sent from proud parents to proud grandparents, were removed because of the possibility of their covering a map. Even lovers’ X’s, meant as kisses, were heartlessly deleted if censors thought they might be a code. (c)
• 
  Boudewijn

  A book about codes and ciphers: how they're made, how they're broken, and the roles they've played since the the beginning of times in war, business, diplomacy, and espionage. Sometimes interesting, other times perhaps a little bit less interesting, with >1000 pages a comprehensive account. Perhaps not your best choice as an introduction to the history of codebreaking, but if you want a definitive account, this is your book.
• 
  Ollivier

  The definitive book on the history of cryptography. Although even with this revised edition, the modern cryptography is clearly not the focus of this book, Bruce Schneier is probabbly better for this. If you are looking for a different view on several historical events, one focused on cryptography, this book is for you.
  
  Awesome barely described it for me. I read a cut-down translated version of the 1967 edition and reading this revised version was like rediscovering the book itself.
• 
  Beck Frost

  What I liked about this book, it is a great start to the discussion of everything crypto. However, let me just get it out - this book is DATED. I love when people say that this is the definitive source, but the truth is that this book is probably only a third of what would have been written if it were to be written today in 2021. And don't be mistaken, that would be outdated in a matter of days upon those publications as well. It is just the nature that as new stuff declassifies, many of the stories change. Here are a few examples of what is known differently today and is just not in the book:
  
  Alan Turing - Full information on what he actually did to create the bombe and their workings.
  The American Bombe manufacturing and how the Americans took over Enigma from the British during the war.
  The scale of women who worked at Arlington Hall.
  The full declassified story on the intelligence that helped with the locating ADM Yamamoto that led to his death.
  Anything pertaining to the Korean War.
  Hedy Lamar and frequency hopping - declassified and collated in the 1980s.
  Native America Code Talkers - declassified and collated mostly in the 1970s.
  P 526, Specifically we know from declassified artifacts from the late 1990s/early 2000s that the FBI was actually an hindrance in the South American investigations of NAZI activity. And that Elizebeth Smith Friedman was the primary working on this project with the FBI many times almost compromising the work she and her team was doing.
  
  These were just some of my favorites that age the book by using the word "recently:"
  P 773, "More recently" was used to describe the book written by Alfred C. Kinsey for Sexual Behavior in the Human Female which was written in 1953.
  P 953, N.D. Andreyev (a Russian linguist) was "recently proposing" and had "just begun" to "show promise" on a method that would enable to men to decipher any language. I had never heard of him or anything about this and I had to heavily research to find that this referenced a paper in 1965.
  
  When I got to the chapter about the NSA, I was excited because finally we are bridging the past with an Agency that still works today. And this chapter reads like a Wikipedia page of who was director and what the budget was at the time. I have to say that I am not disappointed in the chapter though because to write this much back in the 1960s must have been a lot of work to source.
  
  So, read it and get an idea of how the history of crypto flows, but also know that it is actually much more dynamic since WW2 because things age and new items are discovered or declassified to create new narratives. Know that with each year, new supplemental reading is really necessary to keep up because just when you think you know everything about WW2, even more gets released, and eventually we may actually make it to the Korean War, the Vietnam War, the Gulf War....and on and on....
• 
  Arthur Sperry

  This is a very interesting and detailed book about cryptography and the cryptographers who have worked with codes and code breaking over the years. I loved the level of detail and the many fascinating anecdotes that are included.
• 
  Vagabond of Letters, DLitt

  A definitive history of pre-computer cryptography (nothing newer than the Enigma is covered, but the 'deciphering' of lost languages is) which has no theory or practice - it is history of the people and events alone. Writing is somewhat dry. Tarnished additionally by entire paragraphs being sprinkled through the work for no other purpose than to impugn the Bible as 'com[ing] from the merely human minds of a pagan civilization' (p. 914) which 'held the world in bondage to superstition' (p. 913) as long as people believed it, a view which was 'disproved by the discovery of the Epic of Gilgamesh' (p. 914), followed by a list of half a dozen 'plagiarisms' from that work in the Bible, to innumerable other, similar digs, including a discourse on communication with space aliens (according to the author, unfamiliar with Fermi, they're DEFINITELY out there) which have no place in an ostensibly scholarly work on a completely unrelated subject.
  
  Minus one star for both of the above, and dated and becoming more so (nothing on modern ciphers or their inventors, except for a brief mention of Rivest, Shamir, and Adleman in one sentence on p. 987) this would better be entitled 'A History of Cryptographers and Codebreakers to 1959'.
  
  Three stars. Two if you're interested in the cryptography or modern ciphers. Read Schneier, 'Applied Cryptography', Ferguson, 'Cryptographic Engineering', or Anderson, 'Security Engineering' instead.
  
  Singh's 'The Code Book' is much more recent history which gives computers more than a four-page appendix if you can do without the tedious, 70 pages of detail regarding the precise organizations and reorganizations of the eleven German intelligence divisions from 1933-1945.
  
  (Pre-Nov 2018 review)
• 
  Ed Terrell

  The analyses of codes started at time immemorial. The Codebreakers is encyclopedic if not complete and Khan's knowledge is both thorough and entertaining. He is not the first to point out that the greatest codes ever made can and have been brought to their knees through persistence, good luck, and very often the ability to capitalize on human foibles. Solving ciphers is a mix of sweat and inspiration; creating them a remarkable affirmation of human ingenuity. Cryptography is essentially a mathematical undertaking as in y = mx+b. Code breaking involves both deductive and inductive reasoning, starting with analysis, hypothesis, prediction and finally ending in verification or refutation.
  
  The book is an interesting mix of both history and technique The book is a treatise and at 1000 pages covers some of everything.The Notes section is as additional 200 pages and I confess to skipping over large sections not because they were inherently less interesting but I do have a life! From Vigenere's archetypal system of polyalphabetic substitution to one time pads and microdots, the book traces the development of codes into the highly complex and asymmetric forms of D.E.S. and R.S.A that we have today. A great read.
  
  
• 
  Mike

  I read this book a a few years ago. It's fairly long and in places very technical. Translation: lot's of long and good examples of various codes and ciphers. It also clarified the distinction between a "code" and a "cipher", which i f you are like me, you probably thought were the same thing.
  
  Because of it's comprehensiveness and length, it's a somewhat "daunting" book to start, but the author knows his topic, writes well, and includes lots of interesting samples and uses of both codes and ciphers.
  
  There is another similarly-titled book that was first published only a decade ago (versus several wars) which may cover much of the same ground, but in less depth. I strongly recommend this book if you have ever wondered about how these things work and want a full history of the topic.
  
  I'm sure there are shorter, more focused books on specific methods and trends, but if you want a book that covers it all, read this one. Then, you too can follow it up on a book about the NSA!
• 
  Marne Wilson

  I spent a whole summer reading this book when I was laid up in bed with a bum ankle and a heating pad. Besides telling more than I ever thought there was to know about the history of secret communications, it also taught me a lesson on how to write something both scholarly and entertaining. When I was in library school, my professors often told me that my papers were not just well-researched, but also very readable. (One called my 15-page tome on the history of the Copyright Clearance Center "a real page-turner"!) I think I owe the credit for that entirely to this book and David Kahn, who managed to make 1200 pages fly by and leave me wishing for more in the end.
• 
  Josiah Lau

  This book was absolutely riveting.
  I loved the in-depth exploration of not only the history of codes and ciphers, cryptology and cryptanalysis, but also the related areas of linguistics, information theory as well as the unraveling of ancient texts and inscriptions. The logic, creativity and rigor that goes into cryptanalysis and the understanding of ancient records is simply astonishing.
  10/10 for this book, which although well over a thousand pages long was a thoroughly enjoyable read.
• 
  Marco Bitetto

  This is a spell binding account of the history
  of cryptology and cryptoanalysis...
  This is a must read for anyone that wants to
  understand what happened in world history...
  
• 
  Dietrich Legat

  It so happens that my father was a professional codebreaker. He told me a few stories about what really went on in WWII.
  David Kahn comes closest to all I have read and been told about this subject.
• 
  elsalmon L

  Widely regarded as the best account of the history of cryptography up to its publication.
• 
  Behrooz Parhami

  The second edition of Kahn's 1967 book about cryptology has a new preface and an added Chapter 27, entitled "Cryptography Goes Public," which deals with new developments over the three decades since its original publication. The rest of the book is composed of an introductory Chapter 1, followed three uneven parts, as follows:
  
  The Pageant of Cryptology (Chs. 2-19)
  
  Sideshows (Chs. 20-24)
  
  Paracryptology (Chs. 25-26)
  
  Much of our knowledge on coding and codebreaking activities during World War II have come from fairly-recent declassification of secret projects, even though Great Britain alone devoted 30,000 people to its war effort in this area. This lack of knowledge distorted the view of why things happened the way they did. This fact, along with remarkable advances in the field, made a revised edition of the book absolutely necessary.
  
  Cryptology was introduced in Egypt some 3500 years ago, when hieroglyphic writings were modified, not to conceal the meanings, but to turn them into simple puzzles to challenge and delight the readers. This playful use of cryptology was nothing like its deadly-serious applications today. For 3000 years, the period covered in Chapter 2, the use of cryptology proliferated but the field did not enjoy significant advances.
  
  China never showed any interest in cryptology, preferring instead memorization and oral delivery of messages carrying state secrets. India, by contrast, developed several forms of secret writing. One of the strangest forms of secret communication occurred in ancient Persia, where a secret message was written on a slave's scalp, who was then sent out to deliver the message when his hair had regrown. The Roman state used cryptology extensively. Two Caesars employed it routinely, so we have a category of substitution ciphers known as Caesar's Cipher.
  
  Applications of cryptology grew with the spread of Western civilization. The pace of progress accelerated, fed in part by the increased contact with the Muslim world. In the 1500s, Venice has three secretaries dealing with ciphers. Subsequently, more staff positions and significant budgets were devoted to codebreaking. Invention and rapid spread of telegraphy made the need for codes more urgent for privacy and security. And, of course, the Internet revolution and cybersecurity concerns further broadened the use of secret codes, turning them into a most-important computing & communication concern.
  
  This book's comprehensive history of cryptology, when combined with a modern introductory textbook on the topic (such as Nigel Smart's Cryptography, 3rd ed.,
  https://www.cs.umd.edu/~waa/414-F11/I...), provides curious readers with an overview of the very important domain of secret communications.
• 
  Rishabh Jain

  This is a good book. However, I just felt that I had conceived it to be a different kind of book in my mind. I expected more technical information and novel applications. While the book does contain that, it's more so an account of major instances where cryptology played an integral part, something that the book did promise to do. It highlights key moments relevant to cryptology across the ages, has a fascinating account of the tales and the way situations revolving around key cryptologic breakthroughs evolved, and at times gets very interesting.
  However, for me personally, this book lacked a bit of direction. It may not be the case of someone else, but I really felt things proceeding much more in a chronological manner rather than an inherently progressive manner. Also, some parts of the book simple felt irrelevant at times. Owing to these causes, I feel just a tad bit detected with this book. But who knows, maybe I'll come back to this book some time later, and enjoy it as a challenging fictional piece rather than as a technical recollection.
• 
  Tony

  Although dated (this volume was last updated in 1996) David Kahn has written a masterful and comprehensive history of secret writing and the attempts to break those encyphered or encrypted messages. It was fun to render some of these techniques into computer code and it helped me to gain insights into the inners workings of the arious approaches. Equally as interesting were the stories of individuals who labored long and hard to decrypt messages. A big part of the work deals with the military, of course, but Kahn also includes business, rum running and then, with the advent of the computer and the internet cryptography becomes an integral part of most online transactions (
  https://; Signal texting app; VPNs; etc.). This book requires a big investment of your time (1000 pages) but if you are sufficiently interested you will not be disappointed.
• 
  William Schram

  A very comprehensive history of hidden writing, codes, ciphers and other such things. It goes pretty well into depth with how it describes ancient codes and ciphers, how new ones were made and how they were then broken.
  
  It doesn't cover internet security or anything, since this edition of this book was published in 1967. So it is still in the midst of the Cold War. Interestingly, most code breaking was done by linguists and language experts, but that eventually turned into mathematicians.
  
  It doesn't talk about Alan Turing, since at the time of this book being published, it was classified, or at least I think it was.
  
  Anyway, a wonderful tome on how people tried to keep their messages secret.
• 
  Craig

  An exhaustive, and often exhausting, history of cryptology (codes and ciphers). If you want a description and the actual street address of every building that has ever housed a group of cryptanalysts, foreign or domestic, this is the book for you! Ugh. There are some fascinating anecdotes buried in the noise (almost like hidden messages!), but you have to sort through a lot of chaff to find the wheat. The "Side Stories" addenda compose the most readable and engaging section of the book.
• 
  Tommy

  Not absolutely thorough (obviously much has been written on the NSA since this) and some details can be nitpicked at but this is definitely essential for anyone thinking about the history of espionage and the various esoteric arts of secrecy. James Joyce is even brought in!
  
• 
  Kate

  This was a truly monumental book. It addressed most of the events and people which are often omitted in other works. I really liked that the author also gave examples of how ‘cryptography’ was used to discover secret messages in works of Shakespeare or how it helped with reading ancient writings.
• 
  Kaspars Laizans

  A wonderful insight on cryptanalysis and its influence on human history, especially during World Wars. An interesting siurce of trivia on hidden side of political decisionmaking
• 
  Torpor

  My college cryptography class wasn't this good. It dives deep yet remains compelling.