David Kahn > Quotes

“Do it because it needs to be done. Do it to make your world better…just a little at a time.”
― David Kahn, Cape, Spandex, Briefcase: Leadership Lessons from Superheroes

“The multiple human needs and desires that demand privacy among two or more people in the midst of social life must inevitably lead to cryptology wherever men thrive and wherever they write. Cultural diffusion seems a less likely explanation for its occurrence in so many areas, many of them distant and isolated.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Much of the history of cryptology of this time is a patchwork, a crazy quilt of unrelated items, sprouting, flourishing, withering. Only toward the Western Renaissance does the accreting knowledge begin to build up a momentum. The story of cryptology during these years is, in other words, exactly the story of mankind.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“watch out for schools that promise your kids will "experience success." I'm teaching Plato's Dialogues these days, and I noticed that Socrates never let his students experience success. Socrates won the argument every time.”
― David Kahn

“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.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“I said he’s the best at what he does. Not at what I do.”
― David Kahn, Cape, Spandex, Briefcase: Leadership Lessons from Superheroes

“Every weapon of cryptanalytic science—which in the stratospheric realm of this solution drew heavily upon mathematics, using group theory, congruences, Poisson distributions—was thrown into the fray.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“He was also talented in other directions: he played the violin well and was an accomplished artist, exhibiting at, among others, the Chicago Art Institute.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“the most famous of all those who had an acquaintance with cryptology in the Middle Ages was an English customs official, amateur astronomer, and literary genius named Geoffrey Chaucer.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Gorgo, who may be considered the first woman cryptanalyst,”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“From the early days of its existence, cryptology had served to obscure critical portions of writings dealing with the potent subject of magic—divinations, spells, curses, whatever conferred supernatural powers on its sorcerers. The first faint traces of this appeared in Egyptian cryptography. Plutarch reported that “sundry very ancient oracles were kept in secret writings by the priests” at Delphi. And before the fall of the Roman empire, secret writing was serving as a powerful ally of the necromancers in guarding their art from the profane. One of the most famous magic manuscripts, the so-called Leiden papyrus, discovered at Thebes and written in the third century A.D. in both Greek and a very late form of demotic, a highly simplified version of hieroglyphics, employs cipher to conceal the crucial portions of important recipes.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“The more a cipher deviates from the simple form in which one ciphertext letter invariably replaces the same plaintext letter, the harder it is to break.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“The Arabic knowledge of cryptography was fully set forth in the section on cryptology in the Subh al-a ‘sha, an enormous, 14-volume encyclopedia”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“General Joseph O. Mauborgne, who became Chief Signal Officer in October, 1937. Mauborgne had long been interested in cryptology. In 1914, as a young first lieutenant, he achieved the first recorded solution of a cipher known as the Playfair, then used by the British as their field cipher. He described his technique in a 19-page pamphlet that was the first publication on cryptology issued by the United States government. In World War I, he put together several cryptographic elements to create the only theoretically unbreakable cipher, and promoted the first automatic cipher machine, with which the unbreakable cipher was associated. He was among the first to send and receive radio messages in airplanes. As”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“В период «холодной войны» русские сумели вскрыть шифры американского посольства в Москве. Такие подвиги свидетельствуют об их осведомленности, базирующейся на глубоком понимании шифровального дела и криптоанализа. Исходят ли эти знания из врожденной способности русских к естественным наукам, что позволило им первыми запустить искусственные спутники Земли, или же из большого опыта в области криптологии, которая исправно служила коммунистическим диктаторам в России в их борьбе за власть, или же из привычки, которая впиталась в кровь всякому жителю тоталитарного общества, на каждом шагу видеть и разгадывать секреты, или из врожденной любви славян ко всему таинственному в природе, но так или иначе русские вознесли достижения своей страны в криптологии до высоты полета ее космических спутников.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Suetonius, the gossip columnist of ancient Rome, says that Caesar wrote to Cicero and other friends in a cipher in which the plaintext letters were replaced by letters standing three places further down the alphabet, D for a, E for b, etc.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“The only writer of the Middle Ages to describe cryptography instead of just using it was Roger Bacon, the English monk of startlingly modern speculations. In his Epistle on the Secret Works of Art and the Nullity of Magic, written about the middle of the 1200s,”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“He served as a cryptanalyst with the American Expeditionary Forces in World War I, and returned to River-bank to write an 87-page tract that revolutionized cryptanalysis by introducing statistical methods for the first time.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“director tower, a housing high up on the mast”
― David Kahn, Seizing the Enigma: The Race to Break the German U-Boat Codes, 1939–1943

“The task of the cryptanalysts consisted primarily of reconstructing the wiring and switches of the coding wheels—a task made more burdensome by the daily change of plugboard connections.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“cryptology is black magic in itself springs ultimately from a superficial resemblance between cryptology and divination. Extracting an intelligible message from ciphertext seemed to be exactly the same thing as obtaining knowledge by examining the flight of birds, the location of stars and planets, the length and intersections of lines in the hand, the entrails of sheep, the position of dregs in a teacup. In all of these, the wizardlike operator draws sense from grotesque, unfamiliar, and apparently meaningless signs. He makes known the unknown.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“one of the essential elements of cryptography: a deliberate transformation of the writing.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Vātsyāyana’s famous textbook of erotics, the Kāma-sūtra, lists secret writing as one of the 64 arts, or yogas, that women should know and practice.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Extremist sects in Islam cultivated cryptography to conceal their writings from the orthodox.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Tradition attributes to St. Boniface, the Anglo-Saxon missionary who founded monasteries in Germany in the eighth century, the importation to the continent of cryptographic puzzles based on a dots-for-vowels system.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“the conviction in the minds of many people that cryptology is a black art, a form of occultism whose practitioner must, in William F. Friedman’s apt phrase, “perforce commune daily with dark spirits to accomplish his feats of mental jiu-jitsu.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Cryptology served magical purposes frequently throughout the Middle Ages, and even in the Renaissance was still disguising important parts of alchemical formulas.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“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.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“Hildegard von Bingen, an 11th-century nun who saw apocalyptic visions and was later canonized, had a cipher alphabet which she claimed came to her in a flash of inspiration.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

“For written messages, the Chinese would often write on exceedingly thin silk or paper, which they rolled into a ball and covered with wax. The messenger hid the wax ball, or “la wan,” somewhere about his person, or in his rectum, or he sometimes swallowed it.”
― David Kahn, The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet