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Lacida Antica
The Lacida, also called LCD, was a Polish rotor cipher machine. It was designed and produced before World War II by Poland's Cipher Bureau for prospective wartime use by Polish military higher commands. History The machine's name derived from the surname initials of Gwido ''La''nger, Maksymilian ''Ci''ężki and Ludomir ''Da''nilewicz and / or his younger brother, Leonard ''Da''nilewicz. It was built in Warsaw, to the Cipher Bureau's specifications, by the AVA Radio Company. In anticipation of war, before the September 1939 invasion of Poland, two LCDs were sent to France. From spring 1941, an LCD was used by the Polish ''Team Z'' at the Polish-, Spanish- and French-manned Cadix radio-intelligence and decryption center at Uzès, near France's Mediterranean coast. Prior to the machine's production, it had never been subjected to rigorous decryption attempts. Now it was decided to remedy this oversight. In early July 1941, Polish cryptologists Marian Rejewski and Henryk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous member state of the European Union. Warsaw is the nation's capital and largest metropolis. Other major cities include Kraków, Wrocław, Łódź, Poznań, Gdańsk, and Szczecin. Poland has a temperate transitional climate and its territory traverses the Central European Plain, extending from Baltic Sea in the north to Sudeten and Carpathian Mountains in the south. The longest Polish river is the Vistula, and Poland's highest point is Mount Rysy, situated in the Tatra mountain range of the Carpathians. The country is bordered by Lithuania and Russia to the northeast, Belarus and Ukraine to the east, Slovakia and the Czech Republic to the south, and Germany to the west. It also shares maritime boundaries with Denmark and Sweden. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadix
''Cadix'' was a World War II clandestine intelligence center at Uzès, in southern France, from September 1940 to 9 November 1942. During this period southern France was under the control of Vichy France and not occupied by Nazi Germany. At ''Cadix'', the predominantly Polish team of cryptanalysts who had previously worked at ''PC Bruno'' was reassembled, and worked against German and other Axis ciphers, including the German Enigma machine cipher. ''Cadix'' shut down when Germany occupied southern France. History After the German conquest of Poland in 1939, key personnel of the Polish Cipher Bureau escaped to France. Major Gustave Bertrand of French intelligence established ''PC Bruno'', where the Poles worked, via teletype line, with British cryptologists at Bletchley Park to break Enigma. During the German invasion of France, ''PC Bruno'' had to be evacuated. On 22 June 1940, France signed an armistice with Germany. Two days later, Major Bertrand flew the essential perso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic Hardware
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cipher Bureau (Poland)
The Cipher Bureau, in Polish: ''Biuro Szyfrów'' (), was the interwar Polish General Staff's Second Department's unit charged with SIGINT and both cryptography (the ''use'' of ciphers and codes) and cryptanalysis (the ''study'' of ciphers and codes, for the purpose of "breaking" them). The precursor of the agency that would become the Cipher Bureau was created in May 1919, during the Polish-Soviet War (1919–21), and played a vital role in securing Poland's survival and victory in that war. In mid-1931, the Cipher Bureau was formed by the merger of pre-existing agencies. In December 1932, the Bureau began breaking Germany's Enigma ciphers. Over the next seven years, Polish cryptologists overcame the growing structural and operating complexities of the plugboard-equipped Enigma. The Bureau also broke Soviet cryptography. Five weeks before the outbreak of World War II, on 25 July 1939, in Warsaw, the Polish Cipher Bureau revealed its Enigma-decryption techniques and equipment t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotor Machines
In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use in the 1920s–1970s. The most famous example is the German Enigma machine, the output of which was deciphered by the Allies during World War II, producing intelligence code-named ''Ultra''. Description The primary component of a rotor machine is a set of ''rotors'', also termed ''wheels'' or ''drums'', which are rotating disks with an array of electrical contacts on either side. The wiring between the contacts implements a fixed substitution of letters, replacing them in some complex fashion. On its own, this would offer little security; however, before or after encrypting each letter, the rotors advance positions, changing the substitution. By this means, a rotor machine produces a complex polyalphabetic substitution cipher, which changes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christopher Kasparek
Christopher Kasparek (born 1945) is a Scottish-born writer of Polish descent who has translated works by numerous authors, including Ignacy Krasicki, Bolesław Prus, Florian Znaniecki, Władysław Tatarkiewicz, Marian Rejewski, and Władysław Kozaczuk, as well as the Polish–Lithuanian Constitution of 3 May 1791. He has published papers on the history of the World War II era; Enigma decryption; Bolesław Prus and his novel ''Pharaoh''; the theory and practice of translation; logology (science of science); multiple independent discovery; psychiatric nosology; and electronic health records. Life Born in Edinburgh, Scotland, to Józef and Stanisława (SylviaAcknowledgements in [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector (cipher Machine)
A reflector, in cryptology, is a component of some rotor cipher machines, such as the Enigma machine, that sends electrical impulses that have reached it from the machine's rotors, back in reverse order through those rotors. The reflector simplified using the same machine setup for encryption and decryption, but it creates a weakness in the encryption: with a reflector the encrypted version of a given letter can never be that letter itself. That limitation aided World War II code breakers in cracking Enigma encryption. The comparable WW II U.S. cipher machine, SIGABA In the history of cryptography, the ECM Mark II was a cipher machine used by the United States for message encryption from World War II until the 1950s. The machine was also known as the SIGABA or Converter M-134 by the Army, or CSP-888/889 by the ..., did not include a reflector. Other names The reflector is also known as the reversing drum or, from the German, the ''Umkehrwalze'' or ''UKW''. {{crypto-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commutator
In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory. Group theory The commutator of two elements, and , of a group , is the element : . This element is equal to the group's identity if and only if and commute (from the definition , being equal to the identity if and only if ). The set of all commutators of a group is not in general closed under the group operation, but the subgroup of ''G'' generated by all commutators is closed and is called the ''derived group'' or the ''commutator subgroup'' of ''G''. Commutators are used to define nilpotent and solvable groups and the largest abelian quotient group. The definition of the commutator above is used throughout this article, but many other group theorists define the commutator as :. Identities (group theory) Commutator identities are an important tool in group theory. The expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henryk Zygalski
Henryk Zygalski (; 15 July 1908 – 30 August 1978) was a Polish mathematician and cryptologist who worked at breaking German Enigma ciphers before and during World War II. Life Zygalski was born on 15 July 1908 in Posen, German Empire (now Poznań, Poland). He was, from September 1932, a civilian cryptologist with the Polish General Staff's ''Biuro Szyfrów'' (Cipher Bureau), housed in the Saxon Palace in Warsaw. He worked there with fellow Poznań University alumni and Cipher Bureau cryptology-course graduates Marian Rejewski and Jerzy Różycki. Together they developed methods and equipment for breaking Enigma messages. In late 1938, in response to growing complexities in German encryption procedures, Zygalski designed the "perforated sheets," also known as "Zygalski sheets," a manual device for finding Enigma settings. This scheme, like the earlier "card catalog," was independent of the number of connections being used in the Enigma's plugboard, or commutator. After the war ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marian Rejewski
Marian Adam Rejewski (; 16 August 1905 – 13 February 1980) was a Polish mathematician and cryptologist who in late 1932 reconstructed the sight-unseen German military Enigma cipher machine, aided by limited documents obtained by French military intelligence. Over the next nearly seven years, Rejewski and fellow mathematician-cryptologists Jerzy Różycki and Henryk Zygalski developed and used techniques and equipment to decrypt the German machine ciphers, even as the Germans introduced modifications to their equipment and encryption procedures. Five weeks before the outbreak of World War II the Poles, at a conference in Warsaw, shared their achievements with the French and British, thus enabling Britain to begin reading German Enigma-encrypted messages, seven years after Rejewski's original reconstruction of the machine. The intelligence that was gained by the British from Enigma decrypts formed part of what was code-named Ultra and contributed—perhaps decisively—to the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptologist
This is a list of cryptographers. Cryptography is the practice and study of techniques for secure communication in the presence of third parties called adversaries. Pre twentieth century * Al-Khalil ibn Ahmad al-Farahidi: wrote a (now lost) book on cryptography titled the "''Book of Cryptographic Messages''". * Al-Kindi, 9th century Arabic polymath and originator of frequency analysis. * Athanasius Kircher, attempts to decipher crypted messages * Augustus the Younger, Duke of Brunswick-Lüneburg, wrote a standard book on cryptography * Ibn Wahshiyya: published several cipher alphabets that were used to encrypt magic formulas. * John Dee, wrote an occult book, which in fact was a cover for crypted text * Ibn 'Adlan: 13th-century cryptographer who made important contributions on the sample size of the frequency analysis. * Duke of Mantua Francesco I Gonzaga is the one who used the earliest example of homophonic Substitution cipher in early 1400s. * Ibn al-Durayhim: gave detailed d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
