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2.3. Enigma shifrlash qurilmasi. Shifrlash jarayonida bajaradigan algoritm.
The history of the Enigma starts around 1915, with the invention of the rotor-based cipher machine. As usual in history, the rotor machine was invented more or less simultaneously in different parts of the world. In 1917 there were inventions from Edward Hebern in the USA, Arvid Damm in Sweden, Hugo Koch in The Netherlands and Arthur Scherbius in Germany [1].
The inventors of the rotor machine, from left to right: Theo van Hengel, Edward Hebern and Arthur Scherbius.
Invention of the Rotor Machine (1915)
There is one development however, that pre-dates the others, and that is the invention of Theo A van Hengel (1875-1939) and RPC Sprengler (1875-1955), two Dutch naval officers who produced working rotor-based cipher machines for the Dutch War Department (Ministerie van Oorlog) in 1915. This fact was discovered in 2003 and is described in detail in a paper by Karl de Leeuw [2].
Officially though, the Enigma machine was invented by Arthur Scherbius in 1918, right at the end of World War I. After several years of improving his invention, the first machine saw the light of day in 1923. A year earlier he had secured the rights to patent NL10700 of Dutch inventor Hugo Koch for a similar device [4].
It was a rather large typewriter-style machine that was developed by Scherbius' first company Scherbius & Ritter of Berlin-Wansee (Germany), but was built by Gewerkschaft Securitas (later: Chiffriermaschinen AG), also of Berlin. This machine was known as Die Handelsmaschine.
As the machine prints its output directly on a sheet of paper (like a typewriter), it was also known as Schreibende Enigma (printing Enigma). It was first described in a technical article by Scherbius himself in 1923 [5]. As far as we know, none of the early Handelsmaschinen has survived. It was succeeded a year later by the Die schreibende Enigma, that had an improved printing mechanism.
Glowlamp Enigma (1924)
There were a lot of problems with the printing Enigma machines. The first ones had reliability problems with the print wheel and the later model with the type bars. More importantly though, they were extremely expensive to build and would only be suitable for the high-end market.
For this reason, Scherbius developed a machine that produced its output on a lamp panel rather than on paper. The first model was the Enigma A that was introduced in 1924. It was also known as Gluhlampenmaschine (glow lamp machine).
The machine was available for about 1/8th of the price of the printing Enigma and costed RM 1000 1 . The machine is housed in a wooden case and looks pretty much like the later Enigma models, except that the keys are arranged in sequential order (ABCDE...) rather than the more common typewriter order (QWERTZ...).
The standard Enigma C has 26 keys (A-Z) for the input and 26 lamps (A-Z) for the output. The text is scrambled by means of three cipher wheels that protrude the top lid. Each cipher wheel has 26 contacts at either side. Several variants of the Enigma C were produced, such as the so-called Funkschlüssel C (for the German Navy) and a Swedisch variant, both with 28 keys.
The currency in Germany in 1924 was the Reichsmark (RM).
Commercial Enigma (1926)
Unlike the printing Enigma, the glowlamp machines had a reflector (UKW) that made the machine reciproke (symmetric). As a result the settings of the machine for encoding and decoding were identical, which greatly improved its usability. The UKW had two or four fixed positions. The idea for the reflector came from Scherbius' colleague Willy Korn, who would later lead the company.
In 1926, the design of the glow lamp Enigma was drastically improved. A new chassis was developed and the standard (German) keyboard layout (QWERTZ...) was introduced. Furthermore the reflector (UKW) could be set to 26 different positions. It was mounted to the left of the three cipher wheels, which is why this machine is sometimes thought to be a 4-wheel Enigma.
The machine was internally known as model A26 and became known as the Enigma D. Like the Enigma C it was housed in a wooden transit case with a hinged lid. It had several improvements.
A lamp lights up when a key is pressed
The wheels could be accessed more easily (i.e. the top lid could be opened), there was an optional sunlight filter for the lamp panel, and it had a power selector that was mounted to the right of the cipher wheels. The Enigma D became the basis for most of the later machines.
Zählwerk Enigma (1928)
In 1927, a series of new developments were started, all based on the chassis of the Enigma D. First of all there was the Commercial Enigma, that later became known as the Enigma K. There were several variants of this machine, such as the Swiss K that was built for the Swiss Army.
Enigmaning shifrlash qurilmasi quyidagi rasmda tasvirlangan.
3-rasm.Enigma kriptografik shifrlash qurilmasi.
Enigmaning shifrlash usuli quyidagi rasmda berilgan.
Reflektor
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Chap g‘ildirak
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O‘rta g‘ildirak
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O‘ng g‘ildirak
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Statik g‘ildirak
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A
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A A
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A A
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A A
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A
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B
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B B
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B B
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B B
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B
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C
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C C
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C C
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C C
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C
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