|
Playfair Cipher
The Playfair cipher or Playfair square or Wheatstone–Playfair cipher is a manual symmetric encryption technique and was the first literal digram substitution cipher. The scheme was invented in 1854 by Charles Wheatstone, but bears the name of Lord Playfair for promoting its use. The technique encrypts pairs of letters (''bigrams'' or ''digrams''), instead of single letters as in the simple substitution cipher and rather more complex Vigenère cipher systems then in use. The Playfair is thus significantly harder to break since the frequency analysis used for simple substitution ciphers does not work with it. The frequency analysis of bigrams is possible, but considerably more difficult. With 600 possible bigrams rather than the 26 possible monograms (single symbols, usually letters in this context), a considerably larger cipher text is required in order to be useful. History The Playfair cipher was the first cipher to encrypt pairs of letters in cryptologic history. Wheat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Playfair Cipher 01 HI To BM (cropped)
Playfair may refer to: * Playfair (surname) * Playfair (lunar crater) * Playfair (Martian crater) * PlayFair, software that removes Apple's FairPlay DRM file encryption, now succeeded by Hymn (software), Hymn See also *Playfair Project *TS Playfair, TS ''Playfair'', a Canadian sail training vessel *Playfair's axiom named after John Playfair *Playfair cipher, a manual encryption technique invented in 1854 by Charles Wheatstone *Playfair Cricket Annual *Playfair Race Course *Lyon Playfair Library, now known as the Central Library, at Imperial College London {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Playfair Cipher Building Grid Omitted Letters
Playfair may refer to: * Playfair (surname) * Playfair (lunar crater) * Playfair (Martian crater) * PlayFair, software that removes Apple's FairPlay DRM file encryption, now succeeded by Hymn See also *Playfair Project * TS ''Playfair'', a Canadian sail training vessel *Playfair's axiom named after John Playfair *Playfair cipher, a manual encryption technique invented in 1854 by Charles Wheatstone *Playfair Cricket Annual *Playfair Race Course Playfair Race Course (known as the Spokane Interstate Fair from 1901–1935) was the home of horse racing in Spokane, Washington, from 1901 The track started out as a four-furlong (half-mile) flat oval, and expanded to five furlongs () in 1946. ... * Lyon Playfair Library, now known as the Central Library, at Imperial College London {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polybius Square
The Polybius square, also known as the Polybius checkerboard, is a device invented by the ancient Greeks Cleoxenus and Democleitus, and made famous by the historian and scholar Polybius. The device is used for fractionating plaintext characters so that they can be represented by a smaller set of symbols, which is useful for telegraphy, steganography, and cryptography. The device was originally used for fire signalling, allowing for the coded transmission of any message, not just a finite amount of predetermined options as was the convention before. Basic form According to Polybius' ''Histories,'' the device was invented by Cleoxenus and Democleitus, and further developed by Polybius himself. The device partitioned the alphabet into five tablets with five letters each (except for the last one with only four). There are no surviving tablets from antiquity. Letters are represented by two numbers from one to five, allowing the representation of 25 characters using only 5 numeric sym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key (cryptography)
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key’s security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the practice of the same key being used for both encryption and decryption. Asymmetric cryptography Asymmetric cryptography has separate keys for encrypting and decrypting. These keys are known as the public and private keys, respectively. Purpose Since the key pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Wheatstone - Project Gutenberg Etext 13103
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "free man". The Old English descendant of this word was '' Ċearl'' or ''Ċeorl'', as the name of King Cearl of Mercia, that disappeared after the Norman conquest of England. The name was notably borne by Charlemagne (Charles the Great), and was at the time Latinized as ''Karolus'' (as in ''Vita Karoli Magni''), later also as '' Carolus''. Some Germanic languages, for example Dutch and German, have retained the word in two separate senses. In the particular case of Dutch, ''Karel'' refers to the given name, whereas the noun ''kerel'' means "a bloke, fellow, man". Etymology The name's etymology is a Common Germanic noun ''*karilaz'' meaning "free man", which survives in English as churl (< Old English ''ċeorl''), which developed its depre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Friedman
William Frederick Friedman (September 24, 1891 – November 12, 1969) was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett broke Japan's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II. Early life Friedman was born Wolf Friedman ( yi, װאָלףֿ פֿרידמאַן, russian: Вольф Ф. Фридман), in Chişinău, Bessarabia, the son of Frederick Friedman, a Jew from Bucharest who worked as a translator and linguist for the Russian Postal Service, and the daughter of a well-to-do wine merchant. Friedman's family fled Russia in 1892 to escape the virulent anti-Semitism there, ending up in Pittsburgh, Pennsylvania. Three years later, his first name was changed to William. As a child, Friedman was introduced to cryptography in the short story "The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph O
Joseph is a common male given name, derived from the Hebrew Yosef (יוֹסֵף). "Joseph" is used, along with "Josef", mostly in English, French and partially German languages. This spelling is also found as a variant in the languages of the modern-day Nordic countries. In Portuguese and Spanish, the name is "José". In Arabic, including in the Quran, the name is spelled '' Yūsuf''. In Persian, the name is "Yousef". The name has enjoyed significant popularity in its many forms in numerous countries, and ''Joseph'' was one of the two names, along with ''Robert'', to have remained in the top 10 boys' names list in the US from 1925 to 1972. It is especially common in contemporary Israel, as either "Yossi" or "Yossef", and in Italy, where the name "Giuseppe" was the most common male name in the 20th century. In the first century CE, Joseph was the second most popular male name for Palestine Jews. In the Book of Genesis Joseph is Jacob's eleventh son and Rachel's first son, and k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Australian Navy
The Royal Australian Navy (RAN) is the principal naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister of Defence (MINDEF) and the Chief of Defence Force (CDF). The Department of Defence as part of the Australian Public Service administers the ADF. Formed in 1901, as the Commonwealth Naval Forces (CNF), through the amalgamation of the colonial navies of Australia following the federation of Australia. Although it was originally intended for local defence, it became increasingly responsible for regional defence as the British Empire started to diminish its influence in the South Pacific. The Royal Australian Navy was initially a green-water navy, and where the Royal Navy provided a blue-water force to the Australian Squadron, which the Australian and New Zealand governments helped to fund, and that was assigned to the Australia Station. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coastwatchers
The Coastwatchers, also known as the Coast Watch Organisation, Combined Field Intelligence Service or Section C, Allied Intelligence Bureau, were Allied military intelligence operatives stationed on remote Pacific islands during World War II to observe enemy movements and rescue stranded Allied personnel. They played a significant role in the Pacific Ocean theatre and South West Pacific theatre, particularly as an early warning network during the Guadalcanal campaign. Overview Captain Chapman James Clare, district naval officer of Western Australia, proposed a coastwatching programme in 1919. In 1922, the Australian Commonwealth Naval Board directed the Naval Intelligence Division of the Royal Australian Navy to organise a coastwatching service. Walter Brooksbank, a civil assistant to the Director of Naval Intelligence, worked in the 1920s and 1930s to organise a skeleton service of plantation owners and managers whose properties were in strategic locations in northern Austra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coastwatchers
The Coastwatchers, also known as the Coast Watch Organisation, Combined Field Intelligence Service or Section C, Allied Intelligence Bureau, were Allied military intelligence operatives stationed on remote Pacific islands during World War II to observe enemy movements and rescue stranded Allied personnel. They played a significant role in the Pacific Ocean theatre and South West Pacific theatre, particularly as an early warning network during the Guadalcanal campaign. Overview Captain Chapman James Clare, district naval officer of Western Australia, proposed a coastwatching programme in 1919. In 1922, the Australian Commonwealth Naval Board directed the Naval Intelligence Division of the Royal Australian Navy to organise a coastwatching service. Walter Brooksbank, a civil assistant to the Director of Naval Intelligence, worked in the 1920s and 1930s to organise a skeleton service of plantation owners and managers whose properties were in strategic locations in northern Austra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chatham Islands
The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about ten islands within an approximate radius, the largest of which are Chatham Island and Pitt Island (Rangiauria). They include New Zealand's easternmost point, the Forty-Fours. Some of the islands, formerly cleared for farming, are now preserved as nature reserves to conserve some of the unique flora and fauna. The islands were uninhabited when the Moriori people arrived around 1500 CE and developed a peaceful way of life. In 1835 members of the Ngāti Mutunga and Ngāti Tama Māori iwi from the North Island of New Zealand invaded the islands and nearly exterminated the Moriori, enslaving the survivors. Later during the period of European colonisation of New Zealand, the New Zealand Company claimed that the British Crown had never include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Playfair Cipher")
