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МИНОБРНАУКИ РОССИИ
Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования
«РОССИЙСКИЙ ГОСУДАРСТВЕННЫЙ ГУМАНИТАРНЫЙ УНИВЕРСИТЕТ»
(РГГУ)
ИНСТИТУТ ИНФОРМАЦИОННЫХ НАУК И ТЕХНОЛОГИЙ БЕЗОПАСНОСТИ
ФАКУЛЬТЕТ ЗАЩИТЫ ИНФОРМАЦИИ
History of Cryptography
Реферат по дисциплине История Защиты Информации в Зарубежных Странах студента 2-го курса очной формы обучения
Поликушина Кирилла Алексеевича
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Руководитель кандидат исторических наук, доцент Русецкая Ирина Алексеевна
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Contents
Glossary……………………………………………………………….3
Introduction…………………………………………………………... 4
Part 1. Ancient Times – Classical cryptography ……………………..5
Part 2. Al-Kindi – Frequency Analysis……………………………….6
Part 3. The Rise of the West – The Era of the Black Chambers…...…7
Part 4. Room 40 – Zimmermann Telegram…………………………...9
Part 5. Enigma – Way of Mechanization …………………………….11
Part 6. RSA – Public-key Cryptography……………………………..12
Conclusion………………………………………………………..…..13
Glossary
Cryptography (from Greek κρυπτός – hidden and γράφω – writing) is a science about cipher, steganography and other way of hiding a message or its meaning. It’s also include cryptanalysis.
Ciphering is an algorithm, that helps to protect message from reading. Generally cipher use key to change open information to hiden.
Coding, as opposed to the cipher, change type of information. For example, Morse code convert symbols to dot’n’dash code, that can easily can be convert to sound.
Key is a secret number or keyword, etc. that use in algorithm to cipher open text of massage and decipher ciphered text.
Dechipher is a algorithm, that use a known key to ciphered text for getting open text. It’s not a try to break a cipher.
Steganography is a science of hiding text. But it isn’t connect text’s meaning; steganography hides the existence of message.
Cryptanalysis is a part of cryptography contrasted to ciphering. Cryptanalysis teaches how to break cipher.
Frequency analysis is an analysis of counting number of frequency meeting letters in a text.
Introduction
And it may well be doubted whether human ingenuity can construct an enigma of the kind which human ingenuity may not, by proper application, resolve.
- Edgar Allan Poe.2
At the beginning of XX century cryptography has reborn and took its place in the world. In the world of informational technologies people wants to keep their secret and secure important information from contestants. That’s why cryptography so important today. Nowadays it’s a new young science, and it’s far away from classic cryptography: computer technology brought new abilities and set new targets. Ciphers took the first place. But experience of past help to invent new non-standard ways of evolving. Today the good old ideas are still relevant. Also the classic non-computer cryptography continues to evolve.
It’s start a long time ago, when writing began to emerge. People encrypt important government correspondence and diplomatic information, prescriptions and even magic formula. At the same time there were people who want to get confidentiality information. So, together with cryptography was evolve cryptanalysis. Without cryptanalysis, cryptography wouldn’t improve. That’s why evolve of cryptography should always be considered together with evolve of cryptoanalysis
Part 1. Ancient Times – Classical cryptography
When the world was younger by a few thousand years, ciphers already were very popular way to protect a message. Caesar cipher was the simplest and easiest cipher to use. Its algorithm is a alphabetical shift. Caesar changed letter A to letter B, B to C, etc. Width of the shift could be switched and was the key to the cipher. Such cipher named as monoalphabetic replacement cipher.
In fact, there were a lot of different ciphers, codes, math algorithms and tricks, that was very helpful in ciphering. It’ll take a long time to list all of them, so I want to show most interesting and popular tricks. The first trick is a space between words. You should never let it stay, or your cipher would cipher would be very weak. The second trick some more difficult. Ancient Phoenicians, whose alphabet became the prototype for most people, have no vowels in the alphabet. It made studying much shorter, but reading — harder. Same trick has been used in XIV century to make frequency analysis more difficult. Cryptographer-linguist John Ronald Reuel Tolkien in his philological works offers changes vowels to dots over previous consonant. Although much of the work of Professor refers to linguistic cryptography, they will be discussed later, because these works were written in the 20th century
Except ciphers, steganography evolve as well. Special attention pointed at invisible ink. Many ink recipes survived to nowadays. Invisible ink appear after thermal effects, light effect, reagents effect etc.
Another steganography method was Aeneas’ book code. Aeneas recommend to make little needle’s poined in a book.3 It is very simple, but effective device.
There are much more tricks, methods. Cryptographers have a huge collections of them, so much information about classical cryptography, but progress does not stand still, and we are not.
Part 2. Al-Kindi – Frequency Analysis
Cryptology was born among the Arabs. They were the first to discover and write down the methods of cryptanalysis. The people that exploded out of Arabia in the 600s and flamed over vast areas of the known world swiftly engendered one of the highest civilizations that history -had yet seen. Science flowered. Arab medicine and mathematics became the best in the world—from the latter, in fact, comes the word "cipher." Practical arts flourished. Administrative techniques developed. The exuberant creative energies of such a culture, excluded by its religion from painting or sculpture, and inspired by it to an explication of the Holy Koran, poured into literary pursuits.
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 written to afford the secretary class a systematic survey of all the important branches of knowledge. It was completed in 1412 and succeeded in its task. Its author, who lived in Egypt, was Shihab al-DIn abu '!-'Abbas Ahmad ben 'Ali ben Ahmad 'Abd Allah al-Qalqashandi. The cryptologic section, "Concerning the concealment of secret messages within letters," has two parts, one dealing with symbolic actions and allusions, the other with invisible inks and cryptology. Qalqashandi attributed most of his information on cryptology to the writings of Taj ad-Din 'All ibn ad-Duraihim ben Muhammad ath-Tha'alibi al-Mausill, who lived from 1312 to 1361 and held various teaching and official posts under the Mamelukes in Syria and Egypt. Except for a theological treatise, none of his writings is extant, but he is reported to have authored two works on cryptology.4
After explaining that one may write in an unknown language to obtain secrecy, Ibn ad-Duraihim, according to Qalqashandi, gave seven systems of ciphers. This list encompassed, for the first time in cryptography, both transposition and substitution ciphers. Moreover, one system is the first known cipher ever to provide more than one substitute for a plaintext letter. Remarkable and important
The Ibn ad-Duraihim—Qalqashandi exposition begins at the beginning: the cryptanalyst must know the language in which the cryptogram is written. Because Arabic, "the noblest and most exalted of all languages," is "the one most frequently resorted to" (in that part of the world), there follows an extensive discussion of its linguistic characteristics. Lists are given of letters that are never found together in one word, of letters that rarely come together in a word, of combinations of letters that are not possible ("Thus tha' may not precede shin."), and so on. Finally, the exposition gives a list of letters in order of "frequency of usage in Arabic in the light of what a perusal of the Noble Koran reveals." The writers even note that "In non-Koranic writings, the frequency may be different from this." Following which, Qalqashandi explains lucidly the principles of cryptanalysis and demonstrates with two examples. But this knowledge vanished in the Arab decline5.
Part 3. The Rise of the West – The Era of the Black Chambers
Modern western cryptology emerged directly from the flowering of modern diplomacy. The ambassadors' reports were sometimes opened and read, and, if necessary, crypt-analyzed. By the end of the century, cryptology had become important enough for most states to keep full-time cipher secretaries occupied in making up new keys, enciphering and deciphering messages, and solving intercepted dispatches. Sometimes the cryptanalysts were separate from the cipher secretaries and were called in only when needed.
Black chambers were common during the 1700s, but that of Vienna—the Geheime Kabinets-Kanzlei—was reputed to be the best in all Europe.6
It ran with almost unbelievable efficiency. The bags of mail for delivery that morning to the embassies in Vienna were brought to the black chamber each day at 7 a.m. There the letters were opened by melting their seals with a candle. The order of the letters in an envelope was noted and the letters given to a subdirector. He read them and ordered the important parts copied. All the employees could write rapidly, and some knew shorthand. Long letters were dictated to save time, sometimes using four stenographers to a single letter. If a letter was in a language that he did not know, the subdirector gave it to a cabinet employee familiar with it. Two translators were always on hand. All European languages could be read, and when a new one was needed, an official learned it. Armenian, for example, took one cabinet polyglot only a few months to learn, and he was paid the usual 500 florins for his new knowledge. After copying, the letters were replaced in their envelopes in their original order and the envelopes re-sealed, using forged seals to impress the original wax. The letters were returned to the post office by 9:30 a.m.
At 10 a.m., the mail that was passing through this crossroads of the continent arrived and was handled in the same way, though with less hurry because it was in transit. Usually it would be back in the post by 2 p.m., though sometimes it was kept as late as 7 p.m. At 11 a.m., interceptions made by the police for purposes of political surveillance arrived. And at 4 p.m., the couriers brought the letters that the embassies were sending out that day. These were back in the stream of communications by 6:30 p.m. Copied material was handed to the director of the cabinet, who excerpted information of special interest and routed it to the proper agencies, as police, army, or railway administration, and sent the mass of diplomatic material to the court. All told, the ten-man cabinet handled an average of between 80 and 100 letters a day.
Astonishingly, their nimble fingers hardly ever stuffed letters into the wrong packet, despite the speed with which they worked. In one of the few recorded blunders, an intercepted letter to the Duke of Modena was erroneously re-sealed with the closely similar signet of Parma. When the duke noticed the substitution, he sent it to Parma with the wry note, "Not just me—you too." Both states protested, but the Viennese greeted them with a blank stare, a shrug, and a bland profession of ignorance.
England, too, had its black chamber. It began with the cryptanalytic endeavors of John Wallis, the greatest English mathematician before Newton. After his death, it descended through his grandson to reach, on May 14, 1716, Edward Willes, a 22-year-old minister at Oriel College, Oxford.
Willes embarked at once upon a career unique in the annals of cryptology and the church. He not only managed to reconcile his religious calling with an activity once condemned by churchly authorities, but also went on to become the only man in history to use cryptanalytic talents to procure ecclesiastical rewards. Within two years, he had been named rector of Barton, Bedfordshire, for solving more than 300 pages of cipher that exposed Sweden's attempt to foment an uprising in England. He virtually guaranteed his future when he testified before the House of Lords in 1723. Here, Francis Atterbury, Bishop of Rochester, was being tried by his peers for attempting to set a pretender on the English throne.7
Part 4. Room 40 – Zimmermann Telegram
In the history of Cryptanalysis, Room 40 also known as 40 O.B. (Old Building) (latterly NID25) was the section in the Admiralty most identified with the British cryptoanalysis effort during the First World War.
Room 40 was formed in October 1914, shortly after the start of the war. Admiral Oliver, the Director of Naval Intelligence, gave intercepts from the German radio station at Nauen, near Berlin, to Director of Naval Education Alfred Ewing, who constructed ciphers as a hobby. Ewing recruited civilians such as William Montgomery, a translator of theological works from German, and Nigel de Grey, a publisher.8
The basis of Room 40 operations evolved around a German naval codebook, the Signalbuch der Kaiserlichen Marine (SKM), and maps (containing coded squares), which had been passed on to the Admiralty by the Russians. The Russians had seized them from the German cruiser Magdeburg when it ran aground off the Estonian coast on 26 August 1914. Two of the four copies that the warship had been carrying were recovered; one was retained by the Russians and the other passed to the British.9
In October, 1914, the British also obtained the Imperial German Navy's Handelsschiffsverkehrsbuch (HVB), a codebook used by German naval warships, merchantmen, naval zeppelins and U-Boats. This had been captured from the German steamer Hobart by the Royal Australian Navy on 11 October. On 30 November a British trawler recovered a safe from the sunken German destroyer S-119, in which was found the Verkehrsbuch (VB), the code used by the Germans to communicate with naval attachés, embassies and warships overseas.
In March, 1915, the luggage of Wilhelm Wassmuss, a German agent in Persia, was captured and shipped, unopened, to London, where then-Director of Naval Intelligence Admiral Sir William Reginald Hall discovered that it contained the German Diplomatic Code Book, Code No. 13040.
The function of the program was compromised by the Admiralty's insistence upon interpreting Room 40 information in its own way. Room 40 operators were permitted to decrypt, but not to interpret the information they acquired.
The section retained "Room 40" as its informal name even though it expanded during the war and moved into other offices. It has been estimated that Room 40 decrypted around 15,000 German communications, the section being provided with copies of all intercepted communications traffic, including wireless and telegraph traffic. Until May 1917 it was directed by Alfred Ewing, and then direct control passed to Captain (later Admiral) Reginald 'Blinker' Hall, assisted by William Milbourne James.
The Zimmermann Telegram (or Zimmermann Note) was a 1917 diplomatic proposal from the German Empire to Mexico to join the Central Powers, in the event of the United States entering World War I on the Allied side. The proposal was intercepted and decoded by British intelligence. Revelation of the contents outraged American public opinion and helped generate support for the United States declaration of war on Germany in April.10
The message came as a coded telegram dispatched by the Foreign Secretary of the German Empire, Arthur Zimmermann, on 16 January 1917 to the German ambassador in Mexico, Heinrich von Eckardt. Zimmermann sent the telegram in anticipation of the resumption of unrestricted submarine warfare by Germany on 1 February, an act which Germany predicted would draw the neutral U.S. into war on the side of the Allies. The telegram instructed Ambassador Eckardt that if the U.S. appeared likely to enter the war, he was to approach the Mexican Government with a proposal for military alliance, with funding from Germany. Mexico was promised territories in Texas, New Mexico, and Arizona that had been lost to the United States starting in 1836 as parts of the former Republic of Texas, and in 1848 with the Mexican Cession. Eckardt was also instructed to urge Mexico to help broker an alliance between Germany and the Japanese Empire. Mexico, unable to match the U.S. military, ignored the proposal and (after the U.S. entered the war), officially rejected it.11
Part 5. Enigma – Way of Mechanization
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by the German engineer Arthur Scherbius at the end of World War I. The early models were used commercially from the early 1920s, and adopted by military and government services of several countries — most notably by Nazi Germany before and during World War II. Several different Enigma models were produced, but the German military models are the ones most commonly discussed.12
The Polish Cipher Bureau first broke Germany's military Enigma ciphers in December 1932. Five weeks before the outbreak of World War II, on 25 July 1939, they presented their Enigma-decryption techniques and equipment to French and British military intelligence in Warsaw. From 1938 onwards, additional complexity was repeatedly added to the machines, making the initial decryption techniques increasingly unsuccessful. Nonetheless, the Polish breakthrough represented a vital basis for the later British effort. During the war, British codebreakers were able to decrypt a vast number of messages that had been enciphered using the Enigma. The intelligence gleaned from this source, codenamed "Ultra" by the British, was a substantial aid to the Allied war effort.
The exact influence of Ultra on the course of the war is debated; an oft-repeated assessment is that decryption of German ciphers hastened the end of the European war by two years. Winston Churchill told the United Kingdom's King George VI after World War II: "It was thanks to Ultra that we won the war."
Although Enigma had some cryptographic weaknesses, in practice it was only in combination with procedural flaws, operator mistakes, captured key tables and hardware that Allied cryptanalysts were able to be so successful.13
Part 6. RSA – Public-key Cryptography
RSA is an algorithm for public-key cryptography that is based on the presumed difficulty of factoring large integers, the factoring problem. RSA stands for Ron Rivest, Adi Shamir and Leonard Adleman, who first publicly described the algorithm in 1977. Clifford Cocks, an English mathematician, had developed an equivalent system in 1973, but it wasn't declassified until 1997.14
A user of RSA creates and then publishes the product of two large prime numbers, along with an auxiliary value, as their public key. The prime factors must be kept secret. Anyone can use the public key to encrypt a message, but with currently published methods, if the public key is large enough, only someone with knowledge of the prime factors can feasibly decode the message. Whether breaking RSA encryption is as hard as factoring is an open question known as the RSA problem.
The RSA algorithm was publicly described in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman at MIT; the letters RSA are the initials of their surnames, listed in the same order as on the paper.15
MIT was granted U.S. Patent 4,405,829 for a "Cryptographic communications system and method" that used the algorithm in 1983. The patent would have expired on September 21, 2000 (the term of patent was 17 years at the time), but the algorithm was released to the public domain by RSA Security on September 6, 2000, two weeks earlier. Since a paper describing the algorithm had been published in August 1977, prior to the December 1977 filing date of the patent application, regulations in much of the rest of the world precluded patents elsewhere and only the US patent was granted. Had Cocks' work been publicly known, a patent in the US might not have been possible, either.
RSA involves a public key and a private key. The public key can be known to everyone and is used for encrypting messages. Messages encrypted with the public key can only be decrypted in a reasonable amount of time using the private key.
Conclusion
Nowadays cryptography become completely different science. Open key, direct connection with computer evolution, finally appearance of commercial demand… All of this factors make cryptography more than educated person’s hobby. With appearance of computers in the middle of the last century cryptography has entered a new stage of life.
2 "The Gold-Bug" with annotated vocabulary at PoeStories.com
3 Aeneas Tacticus, Asclepiodotus, Onasander. Translated by Illinois Greek Club. Loeb Classical Library.
4 Kahn, David (1996). The Codebreakers
5 Klein-Frank, F. Al-Kindi. In Leaman, O & Nasr, H (2001). History of Islamic Philosophy. London: Routledge. p 165
6 Kahn, David (1996). The Codebreakers
7 Kahn, David (1996). The Codebreakers
8 Kahn, David (1996). The Codebreakers
9 Beesly, Patrick (1982). Room 40: British Naval Intelligence, 1914–1918. New York: Harcourt, Brace, Jovanovich.
102 Andrew, Christopher (1996). For The President's Eyes Only. Harper Collins.
113 Gannon, Paul (2011 ). Inside Room 40: The Codebreakers of World War I. London: Ian Allen Publishing.
12 Singh, Simon (1999). The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography. London: Fourth Estate. p. 127. ISBN 1-85702-879-1.
13 Kahn (1991), Hinsley and Stripp (1993).
14 Rivest, R.; A. Shamir; L. Adleman (1978). "A Method for Obtaining Digital Signatures and Public-Key Cryptosystems"
15 SIAM News, Volume 36, Number 5, June 2003, "Still Guarding Secrets after Years of Attacks, RSA Earns Accolades for its Founders", by Sara Robinson