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116-489: Bradford Hardie III, an American cryptographer during World War II, contributed insider information, German translations from original documents, and intimate real-time operational explanations to The Codebreakers . The Codebreakers is widely regarded as the best account of the history of cryptography up to its publication. William Crowell , the former deputy director of the National Security Agency ,

232-472: A hybrid of the two schemes became the most accepted way for e-commerce operations to proceed. Additionally, the creation of a new protocol known as the Secure Socket Layer, or SSL, led the way for online transactions to take place. Transactions ranging from purchasing goods to online bill pay and banking used SSL. Furthermore, as wireless Internet connections became more common among households,

348-442: A logogram defines the object of which it is an image. Logograms are therefore the most frequently used common nouns; they are always accompanied by a mute vertical stroke indicating their status as a logogram (the usage of a vertical stroke is further explained below); in theory, all hieroglyphs would have the ability to be used as logograms. Logograms can be accompanied by phonetic complements. Here are some examples: In some cases,

464-559: A pintail duck is read in Egyptian as sꜣ , derived from the main consonants of the Egyptian word for this duck: 's', 'ꜣ' and 't'. (Note that ꜣ or [REDACTED] , two half-rings opening to the left, sometimes replaced by the digit '3', is the Egyptian alef . ) It is also possible to use the hieroglyph of the pintail duck without a link to its meaning in order to represent the two phonemes s and ꜣ , independently of any vowels that could accompany these consonants, and in this way write

580-529: A German clerk. This was the greatest breakthrough in cryptanalysis in a thousand years and more, according to historian David Kahn . Rejewski and his mathematical Cipher Bureau colleagues, Jerzy Różycki and Henryk Zygalski , continued reading Enigma and keeping pace with the evolution of the German Army machine's components and encipherment procedures for some time. As the Poles' resources became strained by

696-537: A competition among, candidates for such a cypher algorithm. DES was approved for a short period, but saw extended use due to complex wrangles over the use by the public of high quality encryption. DES was finally replaced by the AES after another public competition organized by the NBS successor agency, NIST. Around the late 1990s to early 2000s, the use of public-key algorithms became a more common approach for encryption, and soon

812-672: A famous story, The Gold-Bug , in which cryptanalysis was a prominent element. Cryptography, and its misuse, were involved in the execution of Mata Hari and in Dreyfus' conviction and imprisonment, both in the early 20th century. Cryptographers were also involved in exposing the machinations which had led to the Dreyfus affair; Mata Hari, in contrast, was shot. In World War I the Admiralty 's Room 40 broke German naval codes and played an important role in several naval engagements during

928-622: A little after Sumerian script , and, probably, [were] invented under the influence of the latter", and that it is "probable that the general idea of expressing words of a language in writing was brought to Egypt from Sumerian Mesopotamia ". Further, Egyptian writing appeared suddenly, while Mesopotamia had a long evolutionary history of the usage of signs—for agricultural and accounting purposes—in tokens dating as early back to c.  8000 BC . However, more recent scholars have held that "the evidence for such direct influence remains flimsy" and that "a very credible argument can also be made for

1044-464: A major part in bringing the United States into the war. In 1917, Gilbert Vernam proposed a teleprinter cipher in which a previously prepared key, kept on paper tape, is combined character by character with the plaintext message to produce the cyphertext. This led to the development of electromechanical devices as cipher machines, and to the only unbreakable cipher, the one time pad . During

1160-631: A mature writing system used for monumental inscription in the classical language of the Middle Kingdom period; during this period, the system used about 900 distinct signs. The use of this writing system continued through the New Kingdom and Late Period , and on into the Persian and Ptolemaic periods. Late survivals of hieroglyphic use are found well into the Roman period , extending into

1276-415: A message (theoretical secrecy, now unconditional security), and the second are those designed to protect against hackers and attacks with finite resources with which to decode a message (practical secrecy, now computational security). Most of Shannon's work focused around theoretical secrecy; here, Shannon introduced a definition for the "unbreakability" of a cipher. If a cipher was determined "unbreakable", it

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1392-628: A noun is recorded from 1590, originally short for nominalized hieroglyphic (1580s, with a plural hieroglyphics ), from adjectival use ( hieroglyphic character ). The Nag Hammadi texts written in Sahidic Coptic call the hieroglyphs "writings of the magicians, soothsayers" ( Coptic : ϩⲉⲛⲥϩⲁⲓ̈ ⲛ̄ⲥⲁϩ ⲡⲣⲁⲛ︦ϣ︦ ). Hieroglyphs may have emerged from the preliterate artistic traditions of Egypt. For example, symbols on Gerzean pottery from c.  4000 BC have been argued to resemble hieroglyphic writing. Proto-writing systems developed in

1508-402: A pair of mathematically related keys, each of which decrypts the encryption performed using the other. Some, but not all, of these algorithms have the additional property that one of the paired keys cannot be deduced from the other by any known method other than trial and error. An algorithm of this kind is known as a public key or asymmetric key system. Using such an algorithm, only one key pair

1624-461: A radically new method of distributing cryptographic keys, which went far toward solving one of the fundamental problems of cryptography, key distribution, and has become known as Diffie–Hellman key exchange . The article also stimulated the almost immediate public development of a new class of enciphering algorithms, the asymmetric key algorithms . Prior to that time, all useful modern encryption algorithms had been symmetric key algorithms , in which

1740-548: A symmetric session key, and the faster symmetric algorithm takes over for the remainder of the message. Asymmetric key cryptography, Diffie–Hellman key exchange, and the best known of the public key / private key algorithms (i.e., what is usually called the RSA algorithm), all seem to have been independently developed at a UK intelligence agency before the public announcement by Diffie and Hellman in 1976. GCHQ has released documents claiming they had developed public key cryptography before

1856-415: A unique reading. For example, the symbol of "the seat" (or chair): Finally, it sometimes happens that the pronunciation of words might be changed because of their connection to Ancient Egyptian: in this case, it is not rare for writing to adopt a compromise in notation, the two readings being indicated jointly. For example, the adjective bnj , "sweet", became bnr . In Middle Egyptian, one can write: which

1972-404: A wire from Alice to Bob. Bob receives the bit stream and decrypts it using his own private key, and then decrypts that bit stream using Alice's public key. If the final result is recognizable as a message, Bob can be confident that the message actually came from someone who knows Alice's private key (presumably actually her if she's been careful with her private key), and that anyone eavesdropping on

2088-486: Is added between consonants to aid in their pronunciation. For example, nfr "good" is typically written nefer . This does not reflect Egyptian vowels, which are obscure, but is merely a modern convention. Likewise, the ꜣ and ꜥ are commonly transliterated as a , as in Ra ( rꜥ ). Hieroglyphs are inscribed in rows of pictures arranged in horizontal lines or vertical columns. Both hieroglyph lines as well as signs contained in

2204-410: Is an exposition on and a worked example of cryptanalysis, including the use of tables of letter frequencies and sets of letters which cannot occur together in one word. The earliest example of the homophonic substitution cipher is the one used by Duke of Mantua in the early 1400s. Homophonic cipher replaces each letter with multiple symbols depending on the letter frequency. The cipher is ahead of

2320-437: Is commonly accepted that this paper was the starting point for development of modern cryptography. Shannon was inspired during the war to address "[t]he problems of cryptography [because] secrecy systems furnish an interesting application of communication theory". Shannon identified the two main goals of cryptography: secrecy and authenticity. His focus was on exploring secrecy and thirty-five years later, G.J. Simmons would address

2436-559: Is fully read as bnr , the j not being pronounced but retained in order to keep a written connection with the ancient word (in the same fashion as the English language words through , knife , or victuals , which are no longer pronounced the way they are written.) Besides a phonetic interpretation, characters can also be read for their meaning: in this instance, logograms are being spoken (or ideograms ) and semagrams (the latter are also called determinatives). A hieroglyph used as

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2552-532: Is needed per user. By designating one key of the pair as private (always secret), and the other as public (often widely available), no secure channel is needed for key exchange. So long as the private key stays secret, the public key can be widely known for a very long time without compromising security, making it safe to reuse the same key pair indefinitely. For two users of an asymmetric key algorithm to communicate securely over an insecure channel, each user will need to know their own public and private keys as well as

2668-443: Is not excluded, but probably reflects the reality." Hieroglyphs consist of three kinds of glyphs: phonetic glyphs, including single-consonant characters that function like an alphabet ; logographs , representing morphemes ; and determinatives , which narrow down the meaning of logographic or phonetic words. As writing developed and became more widespread among the Egyptian people, simplified glyph forms developed, resulting in

2784-504: The /θ/ sound was lost. A few uniliterals first appear in Middle Egyptian texts. Besides the uniliteral glyphs, there are also the biliteral and triliteral signs, to represent a specific sequence of two or three consonants, consonants and vowels, and a few as vowel combinations only, in the language. Egyptian writing is often redundant: in fact, it happens very frequently that a word is followed by several characters writing

2900-559: The Advanced Encryption Standard (AES) in 2001 when NIST announced FIPS 197. After an open competition, NIST selected Rijndael , submitted by two Belgian cryptographers, to be the AES. DES, and more secure variants of it (such as Triple DES ), are still used today, having been incorporated into many national and organizational standards. However, its 56-bit key-size has been shown to be insufficient to guard against brute force attacks (one such attack, undertaken by

3016-522: The Enigma rotor machine , provided more sophisticated and efficient means of encryption; and the subsequent introduction of electronics and computing has allowed elaborate schemes of still greater complexity, most of which are entirely unsuited to pen and paper. The development of cryptography has been paralleled by the development of cryptanalysis — the "breaking" of codes and ciphers . The discovery and application, early on, of frequency analysis to

3132-691: The Fish ciphers ; Max Newman and colleagues designed and deployed the Heath Robinson , and then the world's first programmable digital electronic computer, the Colossus , to help with their cryptanalysis. The German Foreign Office began to use the one-time pad in 1919; some of this traffic was read in World War II partly as the result of recovery of some key material in South America that

3248-671: The Greek adjective ἱερογλυφικός ( hieroglyphikos ), a compound of ἱερός ( hierós 'sacred') and γλύφω ( glýphō '(Ι) carve, engrave'; see glyph ) meaning sacred carving. The glyphs themselves, since the Ptolemaic period , were called τὰ ἱερογλυφικὰ [γράμματα] ( tà hieroglyphikà [grámmata] ) "the sacred engraved letters", the Greek counterpart to the Egyptian expression of mdw.w-nṯr "god's words". Greek ἱερόγλυφος meant "a carver of hieroglyphs". In English, hieroglyph as

3364-670: The Latin and Cyrillic scripts through Greek, and possibly the Arabic and Brahmic scripts through Aramaic. The use of hieroglyphic writing arose from proto-literate symbol systems in the Early Bronze Age c.  the 33rd century BC ( Naqada III ), with the first decipherable sentence written in the Egyptian language dating to the 28th century BC ( Second Dynasty ). Ancient Egyptian hieroglyphs developed into

3480-512: The NSA , acting behind the scenes, it was adopted and published as a Federal Information Processing Standard Publication in 1977 (currently at FIPS 46-3 ). DES was the first publicly accessible cipher to be 'blessed' by a national agency such as the NSA. The release of its specification by NBS stimulated an explosion of public and academic interest in cryptography. The aging DES was officially replaced by

3596-534: The Proto-Sinaitic script that later evolved into the Phoenician alphabet . Egyptian hieroglyphs are the ultimate ancestor of the Phoenician alphabet , the first widely adopted phonetic writing system. Moreover, owing in large part to the Greek and Aramaic scripts that descended from Phoenician, the majority of the world's living writing systems are descendants of Egyptian hieroglyphs—most prominently

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3712-708: The Renaissance , citizens of the various Italian states—the Papal States and the Roman Catholic Church included—were responsible for rapid proliferation of cryptographic techniques, few of which reflect understanding (or even knowledge) of Alberti's polyalphabetic advance. "Advanced ciphers", even after Alberti, were not as advanced as their inventors/developers/users claimed (and probably even they themselves believed). They were frequently broken. This over-optimism may be inherent in cryptography, for it

3828-653: The Second Dynasty (28th or 27th century BC). Around 800 hieroglyphs are known to date back to the Old Kingdom , Middle Kingdom and New Kingdom Eras. By the Greco-Roman period, there were more than 5,000. Scholars have long debated whether hieroglyphs were "original", developed independently of any other script, or derivative. Original scripts are very rare. Previously, scholars like Geoffrey Sampson argued that Egyptian hieroglyphs "came into existence

3944-760: The Soviet Union attacked Poland from the East, they crossed into Romania . From there they reached Paris, France; at PC Bruno , near Paris, they continued working toward breaking Enigma, collaborating with British cryptologists at Bletchley Park as the British got up to speed on their work breaking Enigma. In due course, the British cryptographers – whose ranks included many chess masters and mathematics dons such as Gordon Welchman , Max Newman , and Alan Turing (the conceptual founder of modern computing ) – made substantial breakthroughs in

4060-589: The breaking of the German Enigma machine , which became public knowledge during the 1970s. Hence, not much was said of Alan Turing . It also did not cover the advent of strong cryptography in the public domain, beginning with the invention of public key cryptography and the specification of the Data Encryption Standard in the mid-1970s. The book was republished in 1996, and this new edition included an additional chapter briefly covering

4176-432: The hieratic (priestly) and demotic (popular) scripts. These variants were also more suited than hieroglyphs for use on papyrus . Hieroglyphic writing was not, however, eclipsed, but existed alongside the other forms, especially in monumental and other formal writing. The Rosetta Stone contains three parallel scripts – hieroglyphic, demotic, and Greek. Hieroglyphs continued to be used under Persian rule (intermittent in

4292-673: The tabula recta , a critical component of the Vigenère cipher. Trithemius also wrote the Steganographia . Giovan Battista Bellaso in 1553 first described the cipher that would become known in the 19th century as the Vigenère cipher , misattributed to Blaise de Vigenère . In Europe, cryptography became (secretly) more important as a consequence of political competition and religious revolution. For instance, in Europe during and after

4408-437: The "goose" hieroglyph ( zꜣ ) representing the word for "son". A half-dozen Demotic glyphs are still in use, added to the Greek alphabet when writing Coptic . Knowledge of the hieroglyphs had been lost completely in the medieval period. Early attempts at decipherment were made by some such as Dhul-Nun al-Misri and Ibn Wahshiyya (9th and 10th century, respectively). All medieval and early modern attempts were hampered by

4524-618: The "myth of allegorical hieroglyphs" was ascendant. Monumental use of hieroglyphs ceased after the closing of all non-Christian temples in 391 by the Roman Emperor Theodosius I ; the last known inscription is from Philae , known as the Graffito of Esmet-Akhom , from 394. The Hieroglyphica of Horapollo (c. 5th century) appears to retain some genuine knowledge about the writing system. It offers an explanation of close to 200 signs. Some are identified correctly, such as

4640-787: The 1820s by Jean-François Champollion , with the help of the Rosetta Stone . The entire Ancient Egyptian corpus , including both hieroglyphic and hieratic texts, is approximately 5 million words in length; if counting duplicates (such as the Book of the Dead and the Coffin Texts ) as separate, this figure is closer to 10 million. The most complete compendium of Ancient Egyptian, the Wörterbuch der ägyptischen Sprache , contains 1.5–1.7 million words. The word hieroglyph comes from

4756-504: The 1840s. In particular he placed a notice of his abilities in the Philadelphia paper Alexander's Weekly (Express) Messenger , inviting submissions of ciphers, most of which he proceeded to solve. His success created a public stir for some months. He later wrote an essay on methods of cryptography which proved useful as an introduction for novice British cryptanalysts attempting to break German codes and ciphers during World War I, and

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4872-892: The 1920s, Polish naval-officers assisted the Japanese military with code and cipher development. Mathematical methods proliferated in the period prior to World War II (notably in William F. Friedman 's application of statistical techniques to cryptanalysis and cipher development and in Marian Rejewski 's initial break into the German Army's version of the Enigma system in 1932). By World War II, mechanical and electromechanical cipher machines were in wide use, although—where such machines were impractical— code books and manual systems continued in use. Great advances were made in both cipher design and cryptanalysis , all in secrecy. Information about this period has begun to be declassified as

4988-411: The 1970s, as the public-key cryptography developers, M. E. Hellman and W. Diffie cited Shannon's research as a major influence. His work also impacted modern designs of secret-key ciphers. At the end of Shannon's work with cryptography, progress slowed until Hellman and Diffie introduced their paper involving "public-key cryptography". The mid-1970s saw two major public (i.e., non-secret) advances. First

5104-459: The 4th century AD. During the 5th century, the permanent closing of pagan temples across Roman Egypt ultimately resulted in the ability to read and write hieroglyphs being forgotten. Despite attempts at decipherment, the nature of the script remained unknown throughout the Middle Ages and the early modern period . The decipherment of hieroglyphic writing was finally accomplished in

5220-473: The 6th and 5th centuries BCE), and after Alexander the Great 's conquest of Egypt, during the ensuing Ptolemaic and Roman periods. It appears that the misleading quality of comments from Greek and Roman writers about hieroglyphs came about, at least in part, as a response to the changed political situation. Some believed that hieroglyphs may have functioned as a way to distinguish 'true Egyptians ' from some of

5336-539: The Allies and Axis made a strategic difference in the war. Encryption in modern times is achieved by using algorithms that have a key to encrypt and decrypt information. These keys convert the messages and data into "digital gibberish" through encryption and then return them to the original form through decryption. In general, the longer the key is, the more difficult it is to crack the code. This holds true because deciphering an encrypted message by brute force would require

5452-622: The Deciphering Cryptographic Messages ), in which he described the first cryptanalytic techniques, including some for polyalphabetic ciphers , cipher classification, Arabic phonetics and syntax, and most importantly, gave the first descriptions on frequency analysis. He also covered methods of encipherments, cryptanalysis of certain encipherments, and statistical analysis of letters and letter combinations in Arabic. An important contribution of Ibn Adlan (1187–1268)

5568-772: The Mongols brought about the end of the Islamic Golden Age , cryptography remained comparatively undeveloped. Cryptography in Japan seems not to have been used until about 1510, and advanced techniques were not known until after the opening of the country to the West beginning in the 1860s. Although cryptography has a long and complex history, it wasn't until the 19th century that it developed anything more than ad hoc approaches to either encryption or cryptanalysis (the science of finding weaknesses in crypto systems). Examples of

5684-761: The US victory in the Battle of Midway ; and to the publication of that fact in the Chicago Tribune shortly after the battle, though the Japanese seem not to have noticed for they kept using the JN-25 system. The Americans referred to the intelligence resulting from cryptanalysis, perhaps especially that from the Purple machine, as ' Magic '. The British eventually settled on ' Ultra ' for intelligence resulting from cryptanalysis, particularly that from message traffic protected by

5800-724: The War. The Poles used the Lacida machine, but its security was found to be less than intended (by Polish Army cryptographers in the UK), and its use was discontinued. US troops in the field used the M-209 and the still less secure M-94 family machines. British SOE agents initially used 'poem ciphers' (memorized poems were the encryption/decryption keys), but later in the War, they began to switch to one-time pads . The VIC cipher (used at least until 1957 in connection with Rudolf Abel 's NY spy ring)

5916-589: The West. Ahmad al-Qalqashandi (AD 1355–1418) wrote the Subh al-a 'sha , a 14-volume encyclopedia which included a section on cryptology. This information was attributed to Ibn al-Durayhim who lived from AD 1312 to 1361, but whose writings on cryptography have been lost. The list of ciphers in this work included both substitution and transposition , and for the first time, a polyalphabetic cipher with multiple substitutions for each plaintext letter (later called homophonic substitution). Also traced to Ibn al-Durayhim

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6032-580: The attacker to try every possible key. To put this in context, each binary unit of information, or bit, has a value of 0 or 1. An 8-bit key would then have 256 or 2^8 possible keys. A 56-bit key would have 2^56, or 72 quadrillion, possible keys to try and decipher the message. With modern technology, cyphers using keys with these lengths are becoming easier to decipher. DES, an early US Government approved cypher, has an effective key length of 56 bits, and test messages using that cypher have been broken by brute force key search. However, as technology advances, so does

6148-596: The changes being introduced by the Germans, and as war loomed, the Cipher Bureau , on the Polish General Staff 's instructions, on 25 July 1939, at Warsaw , initiated French and British intelligence representatives into the secrets of Enigma decryption. Soon after the invasion of Poland by Germany on 1 September 1939, key Cipher Bureau personnel were evacuated southeastward; on 17 September, as

6264-488: The channel will need Bob's private key in order to understand the message. Asymmetric algorithms rely for their effectiveness on a class of problems in mathematics called one-way functions, which require relatively little computational power to execute, but vast amounts of power to reverse, if reversal is possible at all. A classic example of a one-way function is multiplication of very large prime numbers. It's fairly quick to multiply two large primes, but very difficult to find

6380-528: The classical notion that the Mesopotamian symbol system predates the Egyptian one. A date of c.  3400 BCE for the earliest Abydos glyphs challenges the hypothesis of diffusion from Mesopotamia to Egypt, pointing to an independent development of writing in Egypt. Rosalie David has argued that the debate is moot since "If Egypt did adopt the idea of writing from elsewhere, it was presumably only

6496-444: The concept which was taken over, since the forms of the hieroglyphs are entirely Egyptian in origin and reflect the distinctive flora, fauna and images of Egypt's own landscape." Egyptian scholar Gamal Mokhtar argued further that the inventory of hieroglyphic symbols derived from "fauna and flora used in the signs [which] are essentially African" and in "regards to writing, we have seen that a purely Nilotic, hence African origin not only

6612-546: The cyber civil-rights group Electronic Frontier Foundation in 1997, succeeded in 56 hours. ) As a result, use of straight DES encryption is now without doubt insecure for use in new cryptosystem designs, and messages protected by older cryptosystems using DES, and indeed all messages sent since 1976 using DES, are also at risk. Regardless of DES' inherent quality, the DES key size (56-bits) was thought to be too small by some even in 1976, perhaps most publicly by Whitfield Diffie . There

6728-689: The earlier "Red" machine used by the Japanese Foreign Ministry, and a related machine, the M-1, used by Naval attachés which was broken by the U.S. Navy's Agnes Driscoll . All the Japanese machine ciphers were broken, to one degree or another, by the Allies. The Japanese Navy and Army largely used code book systems, later with a separate numerical additive. US Navy cryptographers (with cooperation from British and Dutch cryptographers after 1940) broke into several Japanese Navy crypto systems. The break into one of them, JN-25 , famously led to

6844-496: The encryption/decryption operations make asymmetric algorithms computationally expensive, compared to most symmetric algorithms. Since symmetric algorithms can often use any sequence of (random, or at least unpredictable) bits as a key, a disposable session key can be quickly generated for short-term use. Consequently, it is common practice to use a long asymmetric key to exchange a disposable, much shorter (but just as strong) symmetric key. The slower asymmetric algorithm securely sends

6960-469: The events since the original publication. History of cryptography Cryptography, the use of codes and ciphers to protect secrets, began thousands of years ago. Until recent decades, it has been the story of what might be called classical cryptography — that is, of methods of encryption that use pen and paper, or perhaps simple mechanical aids. In the early 20th century, the invention of complex mechanical and electromechanical machines, such as

7076-419: The factors of the product of two large primes. Because of the mathematics of one-way functions, most possible keys are bad choices as cryptographic keys; only a small fraction of the possible keys of a given length are suitable, and so asymmetric algorithms require very long keys to reach the same level of security provided by relatively shorter symmetric keys. The need to both generate the key pairs, and perform

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7192-477: The first person pronoun I . Phonograms formed with one consonant are called uniliteral signs; with two consonants, biliteral signs; with three, triliteral signs. Twenty-four uniliteral signs make up the so-called hieroglyphic alphabet. Egyptian hieroglyphic writing does not normally indicate vowels, unlike cuneiform , and for that reason has been labelled by some as an abjad , i.e., an alphabet without vowels. Thus, hieroglyphic writing representing

7308-463: The first use of permutations and combinations to list all possible Arabic words with and without vowels. The invention of the frequency analysis technique for breaking monoalphabetic substitution ciphers , by Al-Kindi , an Arab mathematician , sometime around AD 800, proved to be the single most significant cryptanalytic advance until World War II. Al-Kindi wrote a book on cryptography entitled Risalah fi Istikhraj al-Mu'amma ( Manuscript for

7424-454: The foreign conquerors. Another reason may be the refusal to tackle a foreign culture on its own terms, which characterized Greco-Roman approaches to Egyptian culture generally. Having learned that hieroglyphs were sacred writing, Greco-Roman authors imagined the complex but rational system as an allegorical, even magical, system transmitting secret, mystical knowledge. By the 4th century CE, few Egyptians were capable of reading hieroglyphs, and

7540-464: The formal writing system used in Ancient Egypt for writing the Egyptian language . Hieroglyphs combined ideographic , logographic , syllabic and alphabetic elements, with more than 1,000 distinct characters. Cursive hieroglyphs were used for religious literature on papyrus and wood. The later hieratic and demotic Egyptian scripts were derived from hieroglyphic writing, as was

7656-425: The fundamental assumption that hieroglyphs recorded ideas and not the sounds of the language. As no bilingual texts were available, any such symbolic 'translation' could be proposed without the possibility of verification. It was not until Athanasius Kircher in the mid 17th century that scholars began to think the hieroglyphs might also represent sounds. Kircher was familiar with Coptic, and thought that it might be

7772-454: The huge volume of enemy messages generated in a global conflict. A few women, including Elizabeth Friedman and Agnes Meyer Driscoll , had been major contributors to US code-breaking in the 1930s and the Navy and Army began actively recruiting top graduates of women's colleges shortly before the attack on Pearl Harbor. Liza Mundy argues that this disparity in utilizing the talents of women between

7888-422: The independent development of writing in Egypt..." While there are many instances of early Egypt-Mesopotamia relations , the lack of direct evidence for the transfer of writing means that "no definitive determination has been made as to the origin of hieroglyphics in ancient Egypt". Since the 1990s, the above-mentioned discoveries of glyphs at Abydos , dated to between 3400 and 3200 BCE, have shed further doubt on

8004-435: The issue of authenticity. Shannon wrote a further article entitled "A mathematical theory of communication" which highlights one of the most significant aspects of his work: cryptography's transition from art to science. In his works, Shannon described the two basic types of systems for secrecy. The first are those designed with the intent to protect against hackers and attackers who have infinite resources with which to decode

8120-442: The key to deciphering the hieroglyphs, but was held back by a belief in the mystical nature of the symbols. The breakthrough in decipherment came only with the discovery of the Rosetta Stone by Napoleon 's troops in 1799 (during Napoleon's Egyptian invasion ). As the stone presented a hieroglyphic and a demotic version of the same text in parallel with a Greek translation, plenty of material for falsifiable studies in translation

8236-524: The latter include Charles Babbage 's Crimean War era work on mathematical cryptanalysis of polyalphabetic ciphers , redeveloped and published somewhat later by the Prussian Friedrich Kasiski . Understanding of cryptography at this time typically consisted of hard-won rules of thumb; see, for example, Auguste Kerckhoffs ' cryptographic writings in the latter 19th century. Edgar Allan Poe used systematic methods to solve ciphers in

8352-550: The left, they almost always must be read from left to right, and vice versa. As in many ancient writing systems, words are not separated by blanks or punctuation marks. However, certain hieroglyphs appear particularly common only at the end of words, making it possible to readily distinguish words. The Egyptian hieroglyphic script contained 24 uniliterals (symbols that stood for single consonants, much like letters in English). It would have been possible to write all Egyptian words in

8468-629: The lines are read with upper content having precedence over content below. The lines or columns, and the individual inscriptions within them, read from left to right in rare instances only and for particular reasons at that; ordinarily however, they read from right to left–the Egyptians' preferred direction of writing (although, for convenience, modern texts are often normalized into left-to-right order). The direction toward which asymmetrical hieroglyphs face indicate their proper reading order. For example, when human and animal hieroglyphs face or look toward

8584-499: The little vertical stroke will be explained further on under Logograms:  – the character sꜣ as used in the word sꜣw , "keep, watch" As in the Arabic script, not all vowels were written in Egyptian hieroglyphs; it is debatable whether vowels were written at all. Possibly, as with Arabic, the semivowels /w/ and /j/ (as in English W and Y) could double as the vowels /u/ and /i/ . In modern transcriptions, an e

8700-436: The manner of these signs, but the Egyptians never did so and never simplified their complex writing into a true alphabet. Each uniliteral glyph once had a unique reading, but several of these fell together as Old Egyptian developed into Middle Egyptian . For example, the folded-cloth glyph (𓋴) seems to have been originally an /s/ and the door-bolt glyph (𓊃) a /θ/ sound, but these both came to be pronounced /s/ , as

8816-480: The manuscript to the government for review without Kahn's permission on 4 March 1966. Kahn and Macmillan eventually agreed to remove some material from the manuscript, particularly concerning the relationship between the NSA and its counterpart in the United Kingdom, GCHQ . The book finishes with a chapter on SETI . Because of the year of its publication, the book did not cover most of the history concerning

8932-529: The need for encryption grew, as a level of security was needed in these everyday situations. Claude E. Shannon is considered by many to be the father of mathematical cryptography. Shannon worked for several years at Bell Labs, and during his time there, he produced an article entitled "A mathematical theory of cryptography". This article was written in 1945 and eventually was published in the Bell System Technical Journal in 1949. It

9048-606: The number of participants increases, or when secure channels aren't available for key exchange, or when, as is sensible cryptographic practice, keys are frequently changed. In particular, if messages are meant to be secure from other users, a separate key is required for each possible pair of users. A system of this kind is known as a secret key, or symmetric key cryptosystem. D-H key exchange (and succeeding improvements and variants) made operation of these systems much easier, and more secure, than had ever been possible before in all of history. In contrast, asymmetric key encryption uses

9164-720: The official British 50-year secrecy period has come to an end, as US archives have slowly opened, and as assorted memoirs and articles have appeared. The Germans made heavy use, in several variants, of an electromechanical rotor machine known as Enigma . Mathematician Marian Rejewski , at Poland's Cipher Bureau , in December 1932 deduced the detailed structure of the German Army Enigma, using mathematics and limited documentation supplied by Captain Gustave Bertrand of French military intelligence acquired from

9280-448: The order of signs if this would result in a more aesthetically pleasing appearance (good scribes attended to the artistic, and even religious, aspects of the hieroglyphs, and would not simply view them as a communication tool). Various examples of the use of phonetic complements can be seen below: Notably, phonetic complements were also used to allow the reader to differentiate between signs that are homophones , or which do not always have

9396-413: The other user's public key. Take this basic scenario: Alice and Bob each have a pair of keys they've been using for years with many other users. At the start of their message, they exchange public keys, unencrypted over an insecure line. Alice then encrypts a message using her private key, and then re-encrypts that result using Bob's public key. The double-encrypted message is then sent as digital data over

9512-699: The other. Beginning around 1990, the use of the Internet for commercial purposes and the introduction of commercial transactions over the Internet called for a widespread standard for encryption. Before the introduction of the Advanced Encryption Standard (AES), information sent over the Internet, such as financial data, was encrypted if at all, most commonly using the Data Encryption Standard (DES). This had been approved by NBS (a US Government agency) for its security, after public call for, and

9628-473: The previous world war. At the end of the War, on 19 April 1945, Britain's highest level civilian and military officials were told that they could never reveal that the German Enigma cipher had been broken because it would give the defeated enemy the chance to say they "were not well and fairly beaten". The German military also deployed several teleprinter stream ciphers . Bletchley Park called them

9744-575: The public domain: the creation of a public encryption standard ( DES ), and the invention of public-key cryptography . The earliest known use of cryptography is found in non-standard hieroglyphs carved into the wall of a tomb from the Old Kingdom of Egypt circa 1900 BC. These are not thought to be serious attempts at secret communications, however, but rather to have been attempts at mystery, intrigue, or even amusement for literate onlookers. Some clay tablets from Mesopotamia somewhat later are clearly meant to protect information—one dated near 1500 BC

9860-535: The publication of Diffie and Hellman's paper. Various classified papers were written at GCHQ during the 1960s and 1970s which eventually led to schemes essentially identical to RSA encryption and to Diffie–Hellman key exchange in 1973 and 1974. Some of these have now been published, and the inventors (James H. Ellis, Clifford Cocks, and Malcolm Williamson) have made public (some of) their work. Egyptian hieroglyphs Ancient Egyptian hieroglyphs ( / ˈ h aɪ r oʊ ˌ ɡ l ɪ f s / HY -roh-glifs ) were

9976-443: The quality of encryption. Since World War II, one of the most notable advances in the study of cryptography is the introduction of the asymmetric key cyphers (sometimes termed public-key cyphers). These are algorithms which use two mathematically related keys for encryption of the same message. Some of these algorithms permit publication of one of the keys, due to it being extremely difficult to determine one key simply from knowledge of

10092-488: The reading of encrypted communications has, on occasion, altered the course of history. Thus the Zimmermann Telegram triggered the United States' entry into World War I; and Allies reading of Nazi Germany 's ciphers shortened World War II, in some evaluations by as much as two years. Until the 1960s, secure cryptography was largely the preserve of governments. Two events have since brought it squarely into

10208-494: The same cryptographic key is used with the underlying algorithm by both the sender and the recipient, who must both keep it secret. All of the electromechanical machines used in World War II were of this logical class, as were the Caesar and Atbash ciphers and essentially all cipher systems throughout history. The 'key' for a code is, of course, the codebook, which must likewise be distributed and kept secret, and so shares most of

10324-428: The same problems in practice. Of necessity, the key in every such system had to be exchanged between the communicating parties in some secure way prior to any use of the system (the term usually used is 'via a secure channel ') such as a trustworthy courier with a briefcase handcuffed to a wrist, or face-to-face contact, or a loyal carrier pigeon. This requirement is never trivial and very rapidly becomes unmanageable as

10440-401: The same sounds, in order to guide the reader. For example, the word nfr , "beautiful, good, perfect", was written with a unique triliteral that was read as nfr : However, it is considerably more common to add to that triliteral, the uniliterals for f and r . The word can thus be written as nfr+f+r , but one still reads it as merely nfr . The two alphabetic characters are adding clarity to

10556-480: The same text, the same phrase, I would almost say in the same word. Visually, hieroglyphs are all more or less figurative: they represent real or abstract elements, sometimes stylized and simplified, but all generally perfectly recognizable in form. However, the same sign can, according to context, be interpreted in diverse ways: as a phonogram ( phonetic reading), as a logogram , or as an ideogram ( semagram ; " determinative ") ( semantic reading). The determinative

10672-583: The scale and technology of Enigma decryption . German code breaking in World War II also had some success, most importantly by breaking the Naval Cipher No. 3 . This enabled them to track and sink Atlantic convoys. It was only Ultra intelligence that finally persuaded the admiralty to change their codes in June 1943. This is surprising given the success of the British Room 40 code breakers in

10788-405: The scytale was for encryption, authentication, or avoiding bad omens in speech. Herodotus tells us of secret messages physically concealed beneath wax on wooden tablets or as a tattoo on a slave's head concealed by regrown hair, although these are not properly examples of cryptography per se as the message, once known, is directly readable; this is known as steganography . Another Greek method

10904-513: The second half of the 4th millennium BC, such as the clay labels of a Predynastic ruler called " Scorpion I " ( Naqada IIIA period, c.  33rd century BC ) recovered at Abydos (modern Umm el-Qa'ab ) in 1998 or the Narmer Palette ( c.  31st century BC ). The first full sentence written in mature hieroglyphs so far discovered was found on a seal impression in the tomb of Seth-Peribsen at Umm el-Qa'ab, which dates from

11020-423: The semantic connection is indirect ( metonymic or metaphoric ): Determinatives or semagrams (semantic symbols specifying meaning) are placed at the end of a word. These mute characters serve to clarify what the word is about, as homophonic glyphs are common. If a similar procedure existed in English, words with the same spelling would be followed by an indicator that would not be read, but which would fine-tune

11136-454: The separate US Army and Navy operations, around Washington, DC. By tradition in Japan and Nazi doctrine in Germany, women were excluded from war work, at least until late in the war. Even after encryption systems were broken, large amounts of work were needed to respond to changes made, recover daily key settings for multiple networks, and intercept, process, translate, prioritize and analyze

11252-485: The spelling of the preceding triliteral hieroglyph. Redundant characters accompanying biliteral or triliteral signs are called phonetic complements (or complementaries). They can be placed in front of the sign (rarely), after the sign (as a general rule), or even framing it (appearing both before and after). Ancient Egyptian scribes consistently avoided leaving large areas of blank space in their writing and might add additional phonetic complements or sometimes even invert

11368-472: The time because it combines monoalphabetic and polyalphabetic features. Essentially all ciphers remained vulnerable to the cryptanalytic technique of frequency analysis until the development of the polyalphabetic cipher, and many remained so thereafter. The polyalphabetic cipher was most clearly explained by Leon Battista Alberti around AD 1467, for which he was called the "father of Western cryptology". Johannes Trithemius , in his work Poligraphia , invented

11484-611: The various Enigmas. An earlier British term for Ultra had been 'Boniface' in an attempt to suggest, if betrayed, that it might have an individual agent as a source. Allied cipher machines used in World War II included the British TypeX and the American SIGABA ; both were electromechanical rotor designs similar in spirit to the Enigma, albeit with major improvements. Neither is known to have been broken by anyone during

11600-585: The war, notably in detecting major German sorties into the North Sea that led to the battles of Dogger Bank and Jutland as the British fleet was sent out to intercept them. However, its most important contribution was probably in decrypting the Zimmermann Telegram , a cable from the German Foreign Office sent via Washington to its ambassador Heinrich von Eckardt in Mexico which played

11716-399: The word: sꜣ , "son"; or when complemented by other signs detailed below sꜣ , "keep, watch"; and sꜣṯ.w , "hard ground". For example:  – the characters sꜣ ;  – the same character used only in order to signify, according to the context, "pintail duck" or, with the appropriate determinative, "son", two words having the same or similar consonants; the meaning of

11832-643: Was Antoine Rossignol ; he and his family created what is known as the Great Cipher because it remained unsolved from its initial use until 1890, when French military cryptanalyst, Étienne Bazeries solved it. An encrypted message from the time of the Man in the Iron Mask (decrypted just prior to 1900 by Étienne Bazeries ) has shed some, regrettably non-definitive, light on the identity of that real, if legendary and unfortunate, prisoner. Outside of Europe, after

11948-517: Was a very complex hand cipher, and is claimed to be the most complicated known to have been used by the Soviets, according to David Kahn in Kahn on Codes . For the decrypting of Soviet ciphers (particularly when one-time pads were reused), see Venona project . The UK and US employed large numbers of women in their code-breaking operation, with close to 7,000 reporting to Bletchley Park and 11,000 to

12064-458: Was considered to have "perfect secrecy". In proving "perfect secrecy", Shannon determined that this could only be obtained with a secret key whose length given in binary digits was greater than or equal to the number of bits contained in the information being encrypted. Furthermore, Shannon developed the "unicity distance", defined as the "amount of plaintext that… determines the secret key." Shannon's work influenced further cryptography research in

12180-572: Was developed by Polybius (now called the " Polybius Square "). The Romans knew something of cryptography (e.g., the Caesar cipher and its variations). David Kahn notes in The Codebreakers that modern cryptology originated among the Arabs , the first people to systematically document cryptanalytic methods. Al-Khalil (717–786) wrote the Book of Cryptographic Messages , which contains

12296-562: Was discarded without sufficient care by a German courier. The Schlüsselgerät 41 was developed late in the war as a more secure replacement for Enigma, but only saw limited use. A US Army group, the SIS , managed to break the highest security Japanese diplomatic cipher system (an electromechanical stepping switch machine called Purple by the Americans) in 1940, before the attack on Pearl Harbor. The locally developed Purple machine replaced

12412-513: Was documented in the Kama Sutra for the purpose of communication between lovers. This was also likely a simple substitution cipher. Parts of the Egyptian demotic Greek Magical Papyri were written in a cypher script. The ancient Greeks are said to have known of ciphers. The scytale transposition cipher was used by the Spartan military, but it is not definitively known whether

12528-456: Was found to encrypt a craftsman's recipe for pottery glaze, presumably commercially valuable. Furthermore, Hebrew scholars made use of simple monoalphabetic substitution ciphers (such as the Atbash cipher ) beginning perhaps around 600 to 500 BC. In India around 400 BC to 200 AD, Mlecchita vikalpa or "the art of understanding writing in cypher, and the writing of words in a peculiar way"

12644-431: Was not read as a phonetic constituent, but facilitated understanding by differentiating the word from its homophones. Most non- determinative hieroglyphic signs are phonograms , whose meaning is determined by pronunciation, independent of visual characteristics. This follows the rebus principle where, for example, the picture of an eye could stand not only for the English word eye , but also for its phonetic equivalent,

12760-488: Was on sample size for use of frequency analysis. In early medieval England between the years 800–1100, substitution ciphers were frequently used by scribes as a playful and clever way to encipher notes, solutions to riddles, and colophons. The ciphers tend to be fairly straightforward, but sometimes they deviate from an ordinary pattern, adding to their complexity, and possibly also to their sophistication. This period saw vital and significant cryptographic experimentation in

12876-518: Was quoted in Newsday magazine: "Before he (Kahn) came along, the best you could do was buy an explanatory book that usually was too technical and terribly dull." The Puzzle Palace (1982), written by James Bamford , gives a history of the writing and publication of The Codebreakers . Kahn, then a journalist, was contracted to write a book on cryptology in 1961. He began writing it part-time, and then he quit his job to work on it full-time. The book

12992-421: Was suddenly available. In the early 19th century, scholars such as Silvestre de Sacy , Johan David Åkerblad , and Thomas Young studied the inscriptions on the stone, and were able to make some headway. Finally, Jean-François Champollion made the complete decipherment by the 1820s. In his Lettre à M. Dacier (1822), he wrote: It is a complex system, writing figurative, symbolic, and phonetic all at once, in

13108-529: Was suspicion that government organizations even then had sufficient computing power to break DES messages; clearly others have achieved this capability. The second development, in 1976, was perhaps even more important, for it fundamentally changed the way cryptosystems might work. This was the publication of the paper New Directions in Cryptography by Whitfield Diffie and Martin Hellman . It introduced

13224-479: Was the publication of the draft Data Encryption Standard in the U.S. Federal Register on 17 March 1975. The proposed DES cipher was submitted by a research group at IBM , at the invitation of the National Bureau of Standards (now NIST ), in an effort to develop secure electronic communication facilities for businesses such as banks and other large financial organizations. After advice and modification by

13340-652: Was then – and remains today – difficult in principle to know how vulnerable one's own system is. In the absence of knowledge, guesses and hopes are predictably common. Cryptography, cryptanalysis , and secret-agent/courier betrayal featured in the Babington plot during the reign of Queen Elizabeth I which led to the execution of Mary, Queen of Scots . Robert Hooke suggested in the chapter Of Dr. Dee's Book of Spirits , that John Dee made use of Trithemian steganography, to conceal his communication with Queen Elizabeth I. The chief cryptographer of King Louis XIV of France

13456-666: Was to include information on the NSA and, according to Bamford, the agency attempted to stop its publication. The NSA considered various options, including writing a negative review of Kahn's work to be published in the press to discredit him. A committee of the United States Intelligence Board concluded that the book was "a possibly valuable support to foreign COMSEC authorities" and recommended "further low-key actions as possible, but short of legal action, to discourage Mr. Kahn or his prospective publishers". Kahn's publisher, Macmillan and Sons , handed over

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