 |
Business | Industries | Finance | Tax |
| Index: > A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
|
|||||
| First Prev [ 1 2 ] Next Last |
In the late 1920s the British were seeking a replacement for their book cipher systems, so two commercial Enigmas were purchased for evaluation. In 1935 the government commissioned Creed & Company to manufacture 'Enigma type' machines. By 1936 Creed had made its first devices, which became known as the RAF Enigma with Type X attachments, and subsequently as "Typex". In February 1937, TypeX MK I was adopted by the UK Air Ministry.
Typex was a five rotor machine, as opposed to three or four in the Enigma. For simplicity the designers did not gear the first two rotors. However, these additional slots meant that the number of different ways rotors could be inserted into the machine increased greatly. In a classic Enigma machine with (say) ten rotors, you can have different ways to arrange them, but in the Typex there were possible combinations.
When faced with the task of decoding Enigma messages, the Allies built many codebreaking machines called bombes, each with one possible selection of rotors during a run. With so many more possibilities, this sort of attack against the Typex was effectively impossible then. The introduction of electronic computers, however, has relieved much of the mechanical design / construct / operate limitations from such attacks since then.
Another improvement the Typex had over the commercial Enigma machine was that each rotor in the machine contained several notches that would turn the "next rotor". Whereas the Enigma would turn after every 26th key press, the Typex might change after 5, 11, 13, and 21 key-presses. This change helps eliminate the number of potential patterns that could be found.
By far the greatest difference from Enigma was to simply use Typex as little as possible. Whereas the Germans routinely encrypted almost all of their messages in their various networks using Enigma, only the British Army high command and the RAF, used the Typex regularly. Other branches still performed all of their encryption by hand using older book-based methods. The supply of the Typex machines was kept severely limited, and no field units were ever allowed to have machines.
From 1943 the Americans and the British signed the Holden Agreement and BRUSA to develop a Combined Cipher Machine (CCM). The American SIGABAIn the history of cryptography, the ECM Mark II was a rotor machine used by the United States from World War II (WWII) until the 1950s. The machine was also known as the SIGABA or Converter M-134 by the Army, or CSP-889 by the Navy, and a modified Navy ve (M-134-C) was similar to Typex in concept, although the Americans never allowed the British to see it, so attachments were built for both that allowed them to read messages created on the other.
It is believed that the CCM was never broken by the Axis. Although a British test cryptanalytic attack made considerable progress, the results were far worse than against the Enigma, due to the increased complexity of the system and the low levels of traffic. A Typex machine was captured by German forces, but it was without rotors. Their inability to use the machine in order to crack Typex messages may have convinced some of them even more of the security of Enigma.
Typex machines continued in use after the war up until the 1970sMillennia: 1st millennium 2nd millennium 3rd millennium Centuries: 19th century 20th century 21st century Decades: 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s Years: 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 Events and trends (the New ZealandFor alternative meanings, see New Zealand (disambiguation). New Zealand is a country formed of two major islands and a number of smaller islands in the southwestern Pacific Ocean. A common Mori name for New Zealand is Aotearoa popularly translated as Land government disposed of its last machine in 1973Events January events January 1 United Kingdom, Ireland, and Denmark enter the European Economic Community now known as the European Union January 3 Columbia Broadcasting System (CBS) sells the New York Yankees for $10 million to a 12-person syndicate led [1]). This was one of the reasons the British kept the UltraThis article is about WWII intelligence material codenamed 'Ultra'. For other usages, see Ultra (disambiguation Ultra (sometimes capitalised ULTRA was the name used by the British for intelligence resulting from decrypts of German communications in World secret for so long; another was that they continued to read the traffic from other nations using Enigma and Typex, while their users continued to consider them secure.
| Politics | Business | Finance |
 |
 |
 |
|