Crypto Timeline 2015 - TimelineJS Version
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-1650The Phaistos DiskThe disc of Phaistos is the most important example of hieroglyphic inscription from Crete and was discovered in 1903 in a small room near the depositories of the “archive chamber”, in the north - east apartments of the palace, together with a Linear A tablet and pottery dated to the beginning of the Neo-palatial period (1700- 1600 B.C.). Both surfaces of this clay disc are covered with hieroglyphs arranged in a spiral zone, impressed on the clay when it was damp. The signs make up groups divided from each other by vertical lines, and each of these groups should represent a word. Forty five different types of signs have been distinguished, of which a few can be identified with the hieroglyphs in use in the Proto- palatial period. Some hieroglyphic sequences recur like refrains, suggesting a religious hymn, and Pernier regards the content of the text as ritual. Others have suggested that the text is a list of soldiers, and lately it has suggested to be a document in the Hittic language in which a king discusses the erection of the Palace of Phaistos ( [Contributor - AFT] [Contributor-KMB] PostUnsolved
-480Persian fleet defeated at Bay of SalamisDemaratus warned the Greeks of an impending Persian attack using steganography. He wrote on wooden tablets and then covered the tablets in wax to conceal the message. Thanks to him, the Greeks were able to prepare and defeat the Persian fleet. [Contributor - RCR, TBM]
-400On the Defense of Fortified Positions was WrittenAeneas Tacticus wrote this book on military science. In it, he devoted an entire chapter to cryptography, describing the military uses of cryptography. In this chapter, Tacticus described several stenganographic techniques, including one that involves puncturing a tiny hole above or below letters in a document to spell out a secret message. Another method he described is steganography with a string. [Contributor - JPZ, JEO] Mollin, R. A. (2005). Codes: The guide to secrecy from ancient to modern times. Florida: Chapman & Hall/CRC. Author: Jeremy NormanMilitary
-196The Rosetta Stone was inscribedThe Rosetta Stone is an Ancient Egyptian granodiorite stele, the engraved text of which provided the key to the modern understanding of Egyptian hieroglyphs. The inscription records a decree that was issued at Memphis in 196 BC on behalf of King Ptolemy V by a council of priests. The decree appears in three texts: the upper one is in ancient Egyptian hieroglyphs, the middle one in Egyptian demotic script, and the lower text in ancient Greek. The Rosetta Stone. (n.d.). Retrieved October 14, 2015, from [Contributor - PAB, CCN, CMG] Culture
-120Polybius Square CipherIn the Polybius square, the letters of the alphabet were arranged left to right, top to bottom in a 5 x 5 square, (when used with the modern 26 letter alphabet, the letters I" and "J" are combined). Five numbers were then aligned on the outside top of the square, and five numbers on the left side of the square vertically. Usually these numbers were arranged 1 through 5. By cross-referencing the two numbers along the grid of the square, a letter could be deduced. In The Histories, he specifies how this cypher could be used in fire signals, where long-range messages could be sent by means of torches raised and lowered to signify the column and row of each letter. This was a great leap forward from previous fire signaling, which could send pre-arranged codes only (such as, 'if we light the fire, it means that the enemy has arrived')." (Wikipedia: Polybius) [Contributor - AFT]érodote.jpgCiphers
100Lives of the Caesars LVI written by SuetoniusThis text provided a description of some of the cryptographic techniques used by Julius Caesar during his Gallic campaigns. The Caesar shift is a cipher in which the plain alphabet is shifted x number of spaces over in the alphabet, moving every corresponding letter the same amount of spaces away from their original position. [Contributor - JPZ]
300Kama-Sutra writtenText written by a Brahmin scholar named Vatsyayana who recommended that women should study 64 arts, including the art of secret writing. Specific techniques, such as random letter pairing are cited. [Contributor - JPZ]Culture
500Atbash CipherThe Atbash cipher is a simple substitution cipher where the first letter of the alphabet is replaced with the last, the second letter with the second to last, and so on. It is obviously weak and susceptible to frequency analysis. [Contributor - AFT]
801873Life of Al KindiAl Kindi, creator of frequency analysis, was born Abū Yūsuf Yaʻqūb ibn Isḥāq al-Kindī. He was born in Iraq and contributed greatly to the fields of Mathematics, Philosophy, Music, Medicine, Astrology, Chemistry, Physics, and Psychology. [Contributor - JH, TRS]
10981179Life of Hildegard of BingenIn addition to many musical compositions, Hildegard also invented the alternative alphabet. Essentially, she created her own language, Lingua Ignota, which was said to be used to communicate privately with her fellow nuns. [Contributor - JPZ]
1391Chaucer's Treatise on the AstrolabeThis treatise includes several encrypted paragraphs replacing plain text with symbols. [Contributor - RL, DPC]
14041438Voynich Manuscript WrittenA mysterious book of about 240 pages containing illustrations and some sort of coded writing continues to baffle cryptographers. The manuscript is named after Wilfrid Voynich, a Polish book dealer who owned it at the beginning of the twentieth century. It is currently owned by Yale and is in one of the libraries there. The listed dates are estimates based on carbon dating, though the actual date the book was written, like the contents of the book, is unknown. [Contributor - STM]
14521519Leonard da VinciDuring his life, he was a great inventor. He is also well-known for his crytographic inventions and techniques. One of his most famous techniques is his mirror-writing, where his writting would only be readable through the use of a mirror. [Contributor - JPZ]
14621516Johannes TrithemiusTrithemius' most famous work is Steganographia (written c.1499. This book is in three volumes, and appears to be about magic - specifically, about using spirits to communicate over long distances. Since the publication of the decryption key to the first two volumes in 1606, they have been known to be actually concerned with cryptography and steganography. Until recently, the third volume was widely still believed to be about magic, but the magical" formulae have now been shown to be covertexts for yet more cryptography content.[3] The work has lent its name to the modern field of steganography." (Wikipedia: Johannes Trithemius) [Contributor - AFT]
1466Leon Alberti invented first polyalphabetic cipherLeon Battista Alberti invented and published the first polyalphabetic cipher, designing a cipher disk to simplify the process. This class of cipher was not broken until the 1800's. Alberti also wrote extensively on the state of the art in ciphers, besides his own invention. Alberti also used his disk for enciphered code. These systems were much stronger than the nomenclator in use by the diplomats of the day and for centuries to come. [Contributor - PAB]
1518Polygraphiae WrittenWritten by Johannes Trithemius, "Polygraphiae" is the first printed book about cryptography. It is also the book in which the "Tabua Recta," or Vigenere square, was first introduced. [Contributor - STM]
15401598Philips of Marnix, Lord of Saint-AldegondeSt. Aldegonde is considered to be the first Dutch cryptographer. For Stadholder William the Silent, he deciphered secret messages that were intercepted from the Spaniards. [Contributor - AFT]
1553Bellaso's CipherGiovan Bellaso offered encrypted passages and this message to challenge cryptanalysts: "The seven appended messages have been accurately compiled according to the concepts taught. They contain some beautiful things that are interesting to know. This will give the skilled and ingenious cryptographers the opportunity to strive to solve them, especially those who assert being capable to solve all kinds of ciphers. If this is true, as many believe, it will not be difficult for them to solve these cryptograms knowing all the rules by which they have been compiled, considering that the different ciphering methods are practically numberless." Bellaso said that he would reveal the contents of the message a year after it was published, however he did not follow up on his word, leaving the cipher still unbroken. ( [Contributor - AFT] on the wikipedia page of Giovan Battista BellasoUnsolved
15861587Babington PlotAnthony Babington and a crew of conspirators believed Mary Stuart, "Queen of Scots" was the rightful heir to the English throne. The Catholics planned to free Mary from prison, assassinate the protestant Elizabeth I, and install Mary as Queen. A Catholic named Gilbert Gifford offered his help in the conspiracy secretly passed ciphered correspondence between Mary and Babington. Gifford was, however, a double agent who passed the letters to Sir Francis Walsingham, one of the Queen's secretaries who had the messages deciphered. The messages were used as evidence in Mary's trial for treason, which ended with her death. [Contributor - STM]
1600Grille Method DevelopedCardinal Richelieu developed a primitive way of sending secret messages by sending a message that could only be decrypted with the use of a special card that had strategically placed holes. These holes would reveal only the desired letters that were a part of the encrypted message. [Contributor - JPZ]
1626Rossignol team become the prominent French cryptanalystsBy decoding a letter sent within the Huguenot army, the French are able to defeat them without shots fired. The city of Realmont is saved. [Contributor - E.B.],_Antoine.jpgMilitary
1671Leibniz Invents Calculating MachineThis calculating machine used the binary scale and served as the foundation for ASCII which continues to be used today. [Contributor - JPZ]
1742House of Commons releases a report on the Deciphering BranchAs early as 1735 parliment members began complaining that their mail appeared to have been opened or tampered with. It was only after this report was released that the members learned that their own deciphering branch had been opening and reading their mail. [Contributor - E.B.]Culture
1750 Shugborough Hall EnscriptionThe Shepherd’s Monument at Shugborough Hall carries a relief (pictured above) that shows a woman watching three shepherds pointing to a tomb. On the tomb is depicted the Latin text “Et in arcadia ego” (”I am also in Arcadia” or “I am even in Arcadia”). The relief is based on a painting by the French artist Nicholas Poussin, known itself as Et in Arcadia ego, but the relief has a number of modifications — most noticeably that it is reversed horizontally. Another difference is a change in which letter of the tomb a shepherd is pointing at. In the painting the letter R in ARCADIA is being pointed to. The finger in the sculpture is broken, but was pointing to the N in IN. The sculpture also adds an extra sarcophagus to the scene, placed on top of the one with the Latin phrase. Below the image of the monument are the following letters: D O.U.O.S.V.A.V.V. M. For adherents of the modern Grail-conspiracy legend, the inscription is alleged to hold a clue to the location of the Holy Grail. Following the claims in the book The Holy Blood and the Holy Grail that Poussin was a member of the Priory of Sion and that the painting contains a message about the location of the grail, it has been speculated that the inscription may encode secrets related to the Priory ( [Contributor - AFT]
1753First description of a telegraph machine"An anonymous letter in a Scottish magazine describes how messages can be sent by 26 cables, one for each letter of the alphabet. The sender could spell out the message by sending pulses of electricity along each wire" (Singh, 60). [Contributor - E.B. & M.L.S] Singh, Simon. The Code Book. Anchor Books, 1999. of the first telegraphs was constructed by Georges Lesage in Geneva, in 1774, using a single wire for each of the letters of the alphabet. Digital image. Lesage's Telegraph. Harvard University, 18 Sept. 1999. Web.
17531839Origin of the TelegraphLetter in a Scottish magazine described a system that would later be called the Wheatstone-Cooke system, which was essentially a way of sending messages across cables, a primitive version of the telegraph. [Contributor - PAB, CSH]
1790Jefferson's Wheel CypherThe invention, by Thomas Jefferson, of a mechanical wheel cypher to encipher messages. The wheel cypher consisted of a number of disks with an alphabet enscribed on their outer edge about a center axis. The disks could be rotated about to form different messages. (Barr, 15) [Contributor - JPZ]
17901832Life of Jean-Francois ChampollionJean-François Champollion (23 December 1790 – 4 March 1832) was a French classical scholar, philologist and orientalist, decipherer of the Egyptian hieroglyphs. Champollion published the first translation of the Rosetta Stone hieroglyphs in 1822, showing that the Egyptian writing system was a combination of phonetic and ideographic signs. [Contributor - PAB]
1791122618711018Life of Charles BabbageCharles Babbage, famous for deciphering the vigenere cipher and the creation of the analytical machine, was born on December 12 1791 and died on October 18 1871. Babbage's analytical machine was created to elminate human error from mathematical computations. Funding for the creation of this machine was pulled by the British government. He never saw his computing machine fully come to life, and he died "a disappointed and embittered man" (University of Minnesota, 2015). [Contributors - JFH, SAT] (Source: University of Minnesota Libraries, Charles Babbage Institute, Who Was Charles Babbage?
1798Pekinese Dogs dispatched by NapoleonNapoleon Bonaparte sent a team of historians, scientists and draftsmen to follow the French invading army and record everything they witnessed. [Contributor - E.B.]People
1799Rosetta Stone discoveredWhile demolishing a wall, soldiers stationed at Fort Julien in Rosetta found a tablet that was essentially a cryptanalytic crib. It contained the same text written three times, once in Greek, once in demotic, and once in hieroglyphics. [Contributor - E.B.]
1799Rosetta Stone rediscoveredOriginally displayed within a temple, the stele was probably moved during the early Christian or medieval period, and eventually used as building material in the construction of a fort at the town of Rashid (Rosetta) in the Nile Delta. It was rediscovered there in 1799 by a soldier of the French expedition to Egypt. As the first ancient bilingual text recovered in modern times, the Rosetta Stone aroused widespread public interest with its potential to decipher the hitherto untranslated ancient Egyptian language. [Contributor - PAB]
18111812The Great Paris Cipher BrokenThe Armies of Napoleon introduced a grand chiffre known as the "Great Paris Cipher" in 1811. It marked the first time Napoleon's Grand Armée used a cipher with more than 200 code numbers. The Great Paris Cipher was based on the ciphers of Louis XIV, though less complicated. The Cipher was completely broken by Major George Scovell, commander of the Duke of Wellington's "Army's Guides" by late 1812. [Contributor - STM]
1822Rosetta Stone Deciphered by Jean-François ChamollionThe Rosetta stone was carved in 196 B.C. and contained the same message in Egyptian hieroglyphics, Egyptian common script, and Greek. During Napoleon's Egyptian campaigns, the stone was found by soldiers and sent back to Europe. Eventually, Champollion used his knowledge of the other scripts to decipher the hieroglyphics, meaning Europeans could now read other hieroglyphic messages. [Contributor - STM]
1823Difference Engine #1 designedFrustrated by many errors in mathematical tables, Babbage had the idea of designing a difference engine number one to calculate polynomials accurately. He worked closely with Joseph Clement until they had a dispute and Clement downed tools and fired his workers. Babbage never ended up seeing his costly project through which would have needed 25,000 parts and would have weighed around 4 tons. [Contributor - PAB, RTM]
1824Precis du systeme hieroglypique is published.Champollion publishes his book that details his work hierolgyphics. It was now possible to read the histories of the Pharoahs as written by the scribes and to translate any hieroglyphics that Egyptian historians encountered. This work also lead to the interpretation of the demotic and heratic languages. Champollion also proved that the hieroglyphic script was essentially "phonetic, not symbolic" from the Pharaonic Period. [Contributor - E.B., LS] Source: Adkins, Lesley and Roy. The Keys of Egypt: the obsession to decipher Egyptian hieroglyphs. New York: Harper Collins, 2000.,204,203,200_PIsitb-sticker-arrow-click,TopRight,35,-76_AA300_SH20_OU01_.jpg Picture of actual book.Culture
1843Edgar Allen Poe's "The Gold Bug"Edgar Allen Poe published "The Gold Bug," which featured a description of frequency analysis and popularized cryptography in fiction. The main character in the short story solves a substitution cipher to find the location of treasure. (Singh, p. 81) [Contributor - DOB, YG, SK]
1845Moriss discovers the Beale ciphersMoriss, the innkeeper whom Beale entrusted his locked box of ciphers, finally opened the box after 23 years in 1845 when he could safely assume that Beale was dead and never returning to reclaim the box. Inside he found three pages of numbers and one sheet of plain English indicating that another message was on its way with the key. The key never made it to Moriss, and since the opening of the box, cryptanalysts have spent lifetimes trying to decipher the three pages of text that supposedly lead to a treasure Beale accumulated in an expedition out West. Only one page has ever been deciphered. The Declaration of Independence was used as a key. [Contributor - E.B.]Unsolved
1852Thackeray uses a Cardano grille in The History of Henry OsmondThe Cardano grille technique, where a stiff paper or card with holes is placed over text to reveal a message, is introduced to the public in William Makepeace Thackeray's novel. This form of stenography was used as recently as World War II. [Contributor - E.B., P.R.]
1854Babbage Cracks the VigenereCharles Babbage likely developed his technique for deciphering the Vigenere cipher this year in response to a challenge from John Hall Brock Thwaits. (Singh, p. 67) [Contributor - DOB]
1854Wheatstone-Playfair Cipher IntroducedA digraphic cipher invented by scientist Charles Wheatstone and popularized by Baron Lyon Playfair. Ciphertext is made based on three rules that apply to a set cipher-square. [Contributor - TSH]
1859First Description of a Tomographic Cipher SystemHorace Mann published his definition of a fractioning, or tomographic, cipher based on the ancient techniques of Polybius, an ancient Greek historian. This technique can be simplistically defined as assigning coordinates to letters by placing them in a checkerboard and assigning the numbers based on their row and column. [Contributor - JPZ]
1861Anson Stager develops Cipher for Union ArmyStager's cipher replaced certain words with codewords; once the replacement was complete, the telegraph operator used a "route" or predetermined word that was placed at the beginning of the message to rearrange the other words in a set way. The recipient then undid the rearrangement and replaced coded words with their plaintext counterparts according to his copy of the codebook. [Contributor - STM]
1862Morriss confides the secret of the Beale ciphersAt the end of his life, Morriss (whom Beale left his ciphers with) tells his confidant Ward about the ciphers. Ward in turn deciphers one of the papers using the Declaration of Independence as a key. [Contributor - E.B.]
1883La Cryptographie militaireDutchman Auguste Kerckhoffs' treatise "La Cryptographie militarie" was an excellent guide and tool for the French with insights into the principles of cryptanalysis. His ideas were implimented into French military tactics on an "industrial scale" [Contributor - JJO]Military
1883Auguste Kerchoff is published in le Journal des Sciences MilitairesKerchoffe's article entitled La Cryptographie Militaire includes the famous Kerchoff's Principle, which states "The design of a system should not require secrecy and compromise of the system should not inconvenience the correspondents" (Wikipedia). [Contributor - AFT]
1885Beale Pamphlets PublishedThree ciphers, supposedly containing the location of a large store of treasure, were published in a pamphlet. Allegedly, Thomas Beale buried treasure near Lynchburg, VA. To this day, there has been no report of the treasure being found and only one of the ciphers has been deciphered (using the Declaration of Independence as a "book cipher." (Singh p. 82) [Contributor - STM]
1887Sherlock Holmes character appears in Arthur Conan Doyle's booksHolmes was featured in 4 novels and 56 short stories. He has become a well known figure associated with detective work. One of his many skills includes the (at least minimal) knowledge of all forms of secret writing. He had written a monograph analysing 160 different ciphers. Retrived from ([Contributor - CSH, SK]
1890Bazeries Reproduces Wheel CypherEtienne Bazeries independently reproduced Jefferson's wheel cypher. His reproduction, often called the Bazeries Cylinder, followed the Jeffersonian model very closely. It also served as a future model for similar ciphers during the world wars. (Barr, 16) [Contributor - JPZ]
18901893Bazeries breaks the Great CipherÉtienne Bazeries deciphered several documents belonging to Louis XIV that were encrypted with the Rossignols' Great Cipher. The documents seem to refer to the fabled Man in the Iron Mask, but their veracity is the subject of some debate. (Singh, p. 54-56) [Contributor - RML]
18901893Etienne Bazeries Breaks Great CipherBazeries struggled through trial and error to decode the Rossignols Syllabic cipher [Contributor - TSH]Ciphers
18911969William FriedmanWilliam Friedman, considered one of the world's greatest cryptographers, worked for the Signal Intelligence Service (SIS) for the US Army Codebreaking division. His biggest achievement was working with his team to decipher Japan's "Purple" Cipher. This gave the US a distinct military advantage throughout WWII. [Contributor - JJO]
1894Marconi invents the radioMarconi found that he could transmit information wirelessly across short distances and patented the idea in 1896. He continued to increase the distance that his wireless communications could travel, ultimately reaching over 3500 km. His invention revolutionized military communication and increased the need for secure encryption. [Contributor - MHG]
1897Dora Bella Cipher is WrittenIn a letter to Dora Penny, Edward Elgar encrypted a message that to this day has proven to be unbreakable. [Contributor - JFH]
1900331Linear B tablets discovered on CreteSir Arthur Evans discovers a vast collection of tablets on Crete, proving his theory that the Mycean civilization was literate and had developed a written language. The most advanced and recent category of tablets (the collection was divided into three categories based on date and sophistication) dated from 1450 to 1375 B.C. and was dubbed Linear B because of the linear nature of the script. [Contributor - E.B., P.R.]
1901Traité Élémentaire de Cryptographie written by DelastelleDelastelle invented the Bifid, Trifid and Four-Square Ciphers and came up with a version of the Playfair Cipher independent of its original creation. The three ciphers he invented all use grids as their basis. [Contributor - STM, DJH]
1903Conan Doyle's "The Dancing Men"Sir Arthur Conan Doyle's Sherlock Holmes story, "The Adventure of the Dancing Men," features a substitution cipher that uses stick figures that appear to be dancing. In the story, the cipher is developed and used by Chicago gangsters. Steganography is also employed here, as the symbols are meant to be passed over as merely children's drawings. As there was no pattern to the cipher, Holmes had to resort to frequency analysis and context clues (such as the name of the messages' recipient) to crack it. "The Dancing Men" remains one of the most popular Holmes stories, ranking in the top ten according to both the Baker Street Irregulars and Conan Doyle himself. (Bantam Classic's <i>Sherlock Holmes: The Complete Novels and Stories Volume I</i> p. 806-831, <i>The Baker Street Journal</i> December 1999 p. 5-11) [Contributor - RML]
1909Secret Intelligence Service FoundedThe Secret Intelligence Service (SIS) was founded in 1909, created in response to fictional books along the lines of Spies of the Kaiser by William Le Queux. The SIS is more commonly known as MI6. Gaining momentum during World War II, MI6 had most of its work during the war years, and began a decline in its prestigue durigng the years that followed. [Contributor - TBM, CMG] [Source:McCrum, R. (2010, September 25). MI6: The History of the Secret Intelligence Service, 1909-1949 by Keith Jeffery. Retrieved October 21, 2015, from] Intelligence Service. for the Secret Intelligence ServiceMilitary
1912Alan Turing is Born,r:0,s:0People
1916Parker Hitt Designs Strip CipherBased on the previous models developed by Jefferson and Bazeries, Hitt was able to adapt this cipher for military use. The M-138 strip cipher was one of the first ciphers used by the Americans during the interwar period and was eventually modified for use later in the war. It greatly improved the Americans encrypting abilities and helped provide an advantage, for a time, during World War II. [Contributor - JPZ]
19162001Claude Elwood ShannonClaude Shannon, known as the father of Information Theory, made many significant contributions to science and cryptography including the Information Theory, the Sampling Theory, and the Communication Theory. Shannon also worked with section D-2 of the National Defense Research Committee during World War II. (Wikipedia: Claude Shannon) [Contributor - AFT]
19171917Gilbert Vernam proposed teletype cipherIn 1917, Gilbert Vernam proposed a teletype cipher in which a previously-prepared "key," kept on paper tape, is "mixed" with the plaintext "message" to produece a ciphertext. This led to the development of electromechanical devices as cipher machines. [Contributor - PAB, LS] [Source - euvers, P., & Simons, M. (2009, January 6). The Vernam Cipher. Retrieved October 19, 2015, from website: Simpson, CipherMachines. 2010-2015Special Transmitter/Distributor for the US military SIGTOT teletype cipherCiphers
1917117Zimmerman Telegram InterceptedArthur Zimmerman's telegram to the German Ambassador to Mexico was intercepted by the British Room 40. (Singh, p. 107) [Contributor - DOB]
1918Americans Develop "Holy Grail of Cryptography"American scientists developed a cipher form that eliminated much of the predictability of the Vigenère. They introduced the idea of a keyword as long as the ciphertext. Longer keywords make the cipher much harder to crack. However, keyphrases that were coherent were still predictable and breakable. In an attempt to create an unbreakable cipher, Major Joseph Mauborgne proposed using a completely random sequence of letters as the keyword. The sender and recipient would use a "onetime pad," using each "keyphrase" only once. Such a cipher is unbreakable, but because it is hard to implement it is used only in the most sensitive of communications. [Contributor - STM]
1918First Enigma Machine inventedArthur Scherbius invented the first Enigma machine in 1918. It operated using a keyboard and a series of rotors to encrypt a message. When the key was turned, the rotors would spin altering the electrical circuit. This changed the encryption key drastically. Enigma was also so complex that the key would not be repeated until around 17,000 letters or 26^3. The Enigma Machine was used by Germany in World War II. [Contributor - TBM, SCE]
1918Choctaw Indians serve as code talkersAlthough the Navajo Code Talkers of World War II are better known, the Choctaw Indians pioneered the use of Native American language in military code back in World War I. 14 Choctaw soldiers in the U.S. Army were trained to use their language as code over the telephone. The system was first put into use in the field in 1918 and was a success. [Contributor - RCR]
1919Chaocipher CreatedJohn Byrne created a cipher that he called the Chaocipher in 1919 that he envisioned helping private businesses everywhere communicate securely. His Chaocipher consisted of two rotors, one containing the plaintext alphabet and the other with the ciphertext alphabet. Rotating one disk causes the other one to rotate as well, but in the other direction. The novel aspect of the Chaocipher algorithm is that each alphabet is slightly modified each time a letter is enciphered or deciphered. Enciphering a plaintext letter requires determining the ciphertext letter that corresponds to the plaintext letter, permuting the left alphabet, and permuting the right alphabet. His cipher was never cracked by anyone until its algorithm was revealed in 2010, but it never received much recognition, either. [Contributor - TRS, JEO] Rubin, M. (2010, July 2). Chaocipher Revealed: The Algorithm. Retrieved from:
1919GIlbert Vernam invents and patents the Vernam Cipher through XOR operationThe XOR operation uses specific impulses or bits to encode characters in the Baudot code. Later in 1919, Vernam invented the Vernam Cipher, which is a symmetrical stream cipher that uses the Boolean XOR function to encode the plaintext and a pseudorandom stream of data of the same text length to generate a ciphertext. The Vernam Cipher has also been claimed to be nearly unbreakable, as the algorithm to hack it would take "millions of years," similar to the time it would take to factor a "200-digit number." [Contributor - LS] Source: Cryptology and Data Secrecy : The Vernam Cipher. (n.d.). Retrieved October 19, 2015, from website: Dong, Math in Network Security, a Crash course5 Bit One-time tape XOR Encryption PrincipleCiphers
1923History of the First World War published by British Royal NavyRestated the fact that interception and cryptanalysis of German communication during World War I aided the Allies in their efforts against the Central Powers [Contributor - JPZ, SCE]
1926Germany begins sending messages enciphered by the EnigmaBritish, French, and American code breakers began to intercept messages that they could not decipher. Germany now had secure communication. Britain lost the ability to monitor German communication, thus losing a major edge going into World War II. When using Enigma, there were always 10 plugboard settings, 3 letter code settings were enciphered twice, and no character could encipher itself. The settings of Engima were changed daily, giving the Germans confidence in the security of their messages. "Simpson, R. (2010). Cipher Machines. Retrieved October 21, 2015, from" [Contributor - CCN, TBM]
1926French begin using trench codesBeginning in 1916, French forces in World War I developed and used trench codes - simple codes to be used for telephone conversations held in the field. This came as a response to heavy French losses from artillery strikes after enemy forces were able to tap into French phone lines and easily discern the position of the French troops. [Contributor - RCR]
1929HIll cipher is publishedLester Hill publishes his article "Cryptography in an Algebraic Alphabet" in which he descibes a method for a cipher that is later named the Hill cipher. The Hill cipher uses linear algebra to encode messages. [Contributor - DPC]
19291929Herbert Hoover is elected president and disbands the black chamber, the American cipher bureau that had been established following WWI. [Contributor - MHG] The precursor to the National Security Agency was shut down because the Secretary of State at the time believed that "gentlemen do not read each other's mail."
It's an interesting anecdote we were reminded of during a visit to the NSA's public museum in Maryland, where it has an exhibit on the so-called "Black Chamber" founded in 1919 by Herbert O. Yardley.
Officially known as The Cipher Bureau, it was America's first peacetime organization dedicated to code breaking. Located in New York City and disguised behind a public-facing commercial code company, its existence was a highly-secret affair that was jointly funded by the State Department and the US Army.
Throughout the 1920's, the bureau cracked thousands of diplomatic messages. Most notably, it intercepted and deciphered the communications of Great Britain and Japan during the Washington Naval Conference in 1921.
"Yardley's team had a major success when it broke the Japanese diplomatic code and learned of the Japanese government's instructions to its ambassadors," an Army historical feature notes. "Naturally, knowing the lowest naval ratio the Japanese were willing to accept put the US in a powerful negotiating position."
But the peace throughout the 1920's meant there was less to intercept, and its budget was continually reduced. Then its time came to a close soon after President Herbert Hoover came into office. Initially, Yardley didn't let new Secretary of State Henry Stimson know about his code-making chamber for a few months.
As James Bamford wrote in "The Puzzle Palace":
Then in May, after Yardley had deciphered a new group of Japanese messages, he decided the time had come to share the dark secret with the man who was paying the bills, and a few selected translations were laid on the Secretary's desk.
Stimson's reaction was immediate and violent. Branding the Black Chamber highly illegal, he at once directed that all its State Department funds be cut off. Since the Chamber was now getting almost its entire support from the State Department, that mean instant doom.
Dealing with ambassadors from friendly nations, Stimson saw interception of those communications as quite disrespectful. "Gentlemen do not read each other's mail," he wrote in his memoirs.
That attitude didn't hold for long, of course. The codebreaking was back in full swing during World War II and beyond, and even at present, the NSA targets friendly and foe embassiesalike. The confirmation of that fact set off a firestorm of criticism from allies after it was revealed by ex-NSA contractor Edward Snowden.
Still, it was Yardley who had the last laugh.
Out of a job in the midst of the Great Depression, Yardley wrote a tell-all memoir of his time secretly breaking codes, called "The American Black Chamber." The NSA's museum described its being published because of a "loophole" in the law, but in reality, there was absolutely no legal precedent to stop the book from coming out.
Though the US government certainly tried. As Bamford notes, it considered prosecution or outright suppression of the book, but ultimately these avenues were rejected since there was no legal standing to go on.
It was published in 1931. A law that closed the "loophole" and prevented any further secrets from being revealed was passed two years later. Cite: Szoldra, Paul. “America Shut down the Original NSA Because 'Gentlemen Do Not Read Each Other's Mail'.” Business Insider, Business Insider, 26 May 2016, [Contributo - EDM]
19301938Rejewski and colleagues broke the Enigma using bombesThrough mathematics, ingenuity, and the help of Hans-Thilo Schmidt, Rejewski and the other Polish cryptanalysts were able to break the German enigma for most of the 1930's, until they handed off their achievements to British cryptanalysts on July 24, 1939. [Contributor - TSH]
1933Chinese Gold Bar CipherIn 1933, seven gold bars were allegedly issued to a General Wang in Shanghai, China. These gold bars appear to represent metal certificates related to a bank deposit with a U.S. Bank. The gold bars themselves have pictures, Chinese writing, some form of script writing, and cryptograms in latin letters. Not surprisingly, there is a dispute concerning the validity of the claim for the deposit. It may help to resolve the dispute if someone can decipher the cryptograms on the bars. Nobody has yet put for the a theory as to their meaning. The Chinese writing has been translated, and discusses a transaction in excess of $300,000,000. It also refers to these gold bars which weigh a total of 1.8 kilograms - Cite: McCurley, Kevin(2017). Cryptograms on Gold Bars from China. Retrieved from : [Contributor - AFT/SJN]
19341938Hagelin develops the M-209 Cipher MachineAt the request of the French Cipher Bureau, Swiss cryptographer Boris Hagelin develops the M-209 cipher machine. The M-209 was used in the field by the U.S. in World War II, and was designated CSP-1500 by the US Navy. [Contributor - RCR, FT], Wikimedia CommonsMilitary
19351935Red Code BrokenThe precursor to the "Purple" Code, the "Red" code was a Japanese code used to encrypt communications. It was a relatively simple code and broken by the Americans in 1935. [Contributor - JJO],r:0,s:0Military
1937SIGABASIGABA was similar to the Enigma in basic theory, in that it used a series of rotors to encipher every character of the plaintext into a different character of ciphertext. Unlike Enigma's three rotors however, the SIGABA included fifteen, and did not use a reflecting rotor. On the downside, the SIGABA was also large, heavy, expensive, difficult to operate, mechanically complex and fragile. It was nowhere near as practical a device as the Enigma, which was smaller and lighter than the radios it was used with. (Wikipedia: SIGABA) [Contributor - AFT]
1939090119450902World War II"The carnage of World War II was unprecedented and brought the world closest to the term “total warfare.” On average 27,000 people were killed each day between September 1, 1939, until the formal surrender of Japan on September 2, 1945. Western technological advances had turned upon itself, bringing about the most destructive war in human history. The primary combatants were the Axis nations of Nazi Germany, Fascist Italy, Imperial Japan, and the Allied nations, Great Britain (and its Commonwealth nations), the Soviet Union, and the United States. Seven days after the suicide of Adolf Hitler, Germany unconditionally surrendered on May 7, 1945. The Japanese would go on to fight for nearly four more months until their surrender on September 2, which was brought on by the U.S. dropping atomic bombs on the Japanese towns of Nagasaki and Hiroshima." Source: [Contributors DOB and SK]
1939D’agapeyeff CipherUnsolved
1941Britain cracked the Enigma Code during WWIIIn a top secret series of raids on German ships and U-boats, Britain was able to siezed several Enigma machines that the Germans used to encode messages during WWI. Although they had already cracked a small portion of the cipher using previous intelligence, British code breakers were able to decipher German messages that they intercepted that had been enciphered by the Enigma machine after this achievement (this information and more on Barratt, John. "Enigma and Ultra- The Cypher War," Military History Online, 2002. Web. [Contributor - TRS, ELS], "Enigma Machine- Polish Labels." 14 May 2007."Enigma Machine- Polish Labels"Military
19421942JN-25 Code BrokenJN-25 was Japan’s premier naval communications code during World War II. This code, used to encrypt Japanese military agendas and operational tactics, was broken by the United States in May 1942 [Contributor - JJO]
19426Americans decipher crucial Purple messageAmerican cryptanalysts, led by William Friedman and Frank Rowlett, were able to decipher a message encoded using PURPLE, the Japanese cipher machine. The message outlined a plan by the Japanese to stage an attack on the Aleutian Islands to lure defences away from their true objective, Midway Island. With this intelligence, the Americans gained the element of surprise and were able to rout the Japanese. [Contributor - RCR, FT]
1942519427First Navajo Code Talkers trainedNavajo was found to be ideal for use as a military code. This was because it was a member of the Na-Dene family of languages, which has no connection to any Asian or European languages, and also because it had not been studied by German students. Within four months of the Japanese attack on Pearl Harbor, 29 Navajo men began an eight-week communications course with the U.S. Marine Corps. By the end of 1942, there was a request for 83 more. Over the course of the war, as many as 420 Navajo served as Code Talkers. Jevec, Adam and Lee Ann Potter. "Memorandum re the Enlistment of Navajo Indians." Social Education 65, 5 (September 2001): 262-268 [Contributor - RCR, ELS]
1943SIGSALY put into useAfter coming to suspect that the A-3 telephone scrambler had been compromised, the Allies turned to a new method of encoding vocal communications called SIGSALY. It encrypted voices through the use of a voice mask that took voices, ran a series of analyses on their wavelengths, and then converted them back into voice waveform. SIGSALY was developed by A.B. Clark and others at Bell Telephone Labs. SIGSALY provided excellent security and was never cracked by the Germans. [Contributor - RCR, YG] Source:,
1943JFK rescued thanks to Playfair CipherFuture President John F. Kennedy Jr. was rammed by a Japanese destroyer in the Solomon Islands, and used the Playfair Cipher to encrypt a message to an Australian Coastwatcher. The Coastwatcher decrypted the message with the keyword “ROYAL NEW ZEALAND NAVY”, and soon thereafter rescued Kennedy and his crew. <> [Contributor - TSH] F. Kennedy Presidential Library and Museum"PC101 Lt. (jg) John F. Kennedy aboard the PT-109""Lt. (jg) John F. Kennedy aboard the PT-109 in the South Pacific, 1943."People
1944Invention of the German Rasterschlüssel 44The Rasterschlüssel 44 (RS 44) was the perfect German cipher for low-level encryption of military data, especially the "traffic" during the Second World War. It took the "Allied codebreakers so much time to break it" that it wasn't worth the relatively insubstantial information decrypted, and wasn't of "tactical use." [Contributor - LS] Source: Rasterschlüssel 44. (2014). Retrieved October 19, 2015, from website: grid of the Rasterschlüssel 44
1949The Mathematical Theory of Communication was publishedDuring 1949, Claude Shannon, arguably the father of mathematical cryptography, published "Communication Theory of Secrecy" in the "Bell System Technical Journal" and a little later the book "The Mathematical Theory of Communication" with Warren Weaver. These established a solid theoretical basis for cryptography and also for much of cryptanalysis. [Contributor - PAB]
1951NSA foundedThe United State's National Security Agency is founded [Contributor - DPC]
1953Evidence for the Greek Dialect of the Mycean Archives is published in The Jounal of Hellenic StudiesThe work is a combined effort of the knowledge of Greek and decipherment held by Ventris and Chadwick. In it, they propose that Linear B is actually written in Greek, revolutionizing the way historians view the Mycean/Minoan history. From this, many have hypothesized that Linear A is written in a Minoan language that was transformed into Linear B when the Myceans conquered the Minoans. [Contributor - E.B.] - J.T. Killen: A Companion to Linear B: Mycenaean Texts and Their World, ed Morpurgo Davies and Y DuhouxVentris studying a Linear B tabletCulture
1954The Silent YearsJohn Byrne published this autobiography to publicize information about his Chaocipher because it had received much less attention than he expected it would. In it, he challenges readers to figure out how he enciphered given plaintext to create his ciphertext. [Contributor - TRS]
1954Alan Turing diesWhen it was discovered that he was a homosexual, he was forced to meet with a psychiatrist and was placed on hormone treatment. He was also not allowed to continue work on the computer. He became depressed and eventually committed suicide on June 4, 1954. [Contributor - TBM]
1964The Codebreakers is publishedDavid Kahn's book, "The Codebreakers" is published. [Contributor - DPC]
1968Navajo code declassifiedThe Navajo were recognized as soldiers following the war, but their role in securing communications remained classified until the year 1968. Finally, they were given the full recognition and honor they deserved for their contribution to the Allied victory in World War II. [Contributor - RCR]
1968Quantum Cryptography first inventedStephen Wiesner, a grad student at Columbia University, comes up with the idea for quantum encryption for "quantum money" which would make forgery impossible. He understood that tampering with encryption (i.e. trying to intercept a message) would render it indecipherable. However, his idea was too far ahead of his time, and quantum money was much too costly to gain any popularity at the time. [Contributor - TSH]
1969Zodiac CiphersThe Zodiac killer, who was never caught, sent multiple ciphers of varying lengths to several San Francisco newspapers, which were supposed to reveal information about the murders he had committed. He demanded that they be published so that the public could crack them. While some were cracked within days of receipt, others still remain unbroken to this day. [Contributor - TRS, MAG, JC] on Zodiac Killer Unsolved 340-character cipher Wikipedia page, pulled from zodiackillerciphers.comAn image of the unsolved 340-character Zodiac cipher, sent to Northern California newspapers on Nov. 8, 1969.Ciphers
1972The Pioneer plaquesNASA attached a metal plaque onto the Pioneer spacecraft 10 and 11. On the plaque is "a diagram of the transition of neutral atomic hydrogen, a universal yardstick providing a unit of both time and length throughout the universe; a radial representation of where Earth was located in relation to other celestial objects; and figures of both a man and a woman (Pearlman)." The plaque represents the most basic of human structure and concepts in hopes to be comprehendable to an extraterestrial species. The property of hydrogen is the key to the plaques cypher text. [Contributors - SCE] Found on Scientific American An drawn image of the plaque that depicts the message sent by NASATechnology
1973Clifford Cocks discovers function to utilize asymmetric cryptographyClifford Cocks, a graduate of Cambridge University, discovered a one way equation that could be used in asymmetric cryptography. He did this within his first two weeks at the GCHQ. Other cryptographers and mathematicians in the GCHQ had been working on this problem for three years; Cocks solved it in less than a half-hour. [Contributor - TBM]
1973Public Key Cryptography Developed by GCHQJames H. Ellis, Clifford Cocks, and Malcolm Williamson of the UK's GCHQ developed "non-secret encryption" with use of asymmetrical algorithms, allowing information to be encrypted with one key and decrypted with another. All users have a public key, which is widely distributed, and a private key which is kept secret. Information intended for a specific recipient is encrypted with his public key and can only be decrypted by his private key. In 1976, Whitfield Diffie and Martin Hellman developed the same system publicly and were given credit while the GCHQ work was not properly credited until 1997 because of the top-secret nature of the information. [Contributor - STM] In 2001, the 4th International Workshop on Practice and Theory in Public-Key Cryptosystems met, and publsihed several papers about the current viability of public key cryptography. Kazukuni Kobara and Hideki Imai authored the piece about current public-key cryptosystems. Surprisingly, RSA, one of the original codes used for public-key encryption, is still in use, and will be until the advent of a true quantum computer. (Kazukuni Kobara and Hideki Imai, p. 1) [Contributor-ACH]
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