KL7 轉子密碼機、KL7 密碼機、TSECKL7、Adonis、舊稱 AFSAM7，是著名密碼機。美國海陸空三軍皆引入過該機器。是美國武裝部隊中使用最廣泛的加密機器，並且是第一臺支援安全抵禦已知明文攻擊的大型網路機器。 was an offline nonreciprocal rotor encryption machineA History of US Communications Security the David G Boak Lectures National Security Agency NSA Volume I 1973 partially released 2008 additional portions declassified October 14 2015 歷史與發展 In 1952 the machine was introduced by AFSAs successor the US National Security Agency in the US Army Navy and Air Force In the early 1960s the AFSAM7 was renamed TSECKL7 following the new standard crypto nomenclature It was the most widely used crypto machine in the US armed forces until the mid1960s and was the first machine capable of supporting large networks that was considered secure against known plaintext attack Some 25000 machines were in use in the mid1960s The KL7 was also used by several NATO countries until 1983 An 8rotor version sent indicators in the clear and was code named POLLUX The encrypted or decrypted output of the machine was printed on a small paper ribbon It was the first cipher machine to use the reentry reflexing principle discovered by Albert W Small which reintroduces the encryption output back into the encryption process to reencipher it again The research for the new cipher machine designated MX507 was initiated in 1945 by the Army Security Agency ASA as a successor for the SIGABA and the less secure Hagelin M209 Its development was turned over to the newly formed Armed Forces Security Agency AFSA in 1949 The machine was renamed AFSAM7 which stands for Armed Forces Security Agency Machine No 7 It was the first crypto machine developed under one centralized cryptologic organisation as a standard machine for all parts of the armed forces and it was the first cipher machine to use electronics vacuum tubes apart from the British ROCKEX which was developed during World War 2 說明 The KL7 was designed for offline operation It was about the size of a Teletype machine and had a similar threerow keyboard with shift keys for letters and figures The KL7 produced printed output on narrow paper strips that were then glued to message pads When encrypting it automatically inserted a space between fiveletter code groups One of the reasons for the five letter groups was messages might be given to a morse code operator The number of five letter groups was easily verified when transmitted There was an adaptor available the HL1X22 that allowed 5level Baudot punched paper tape from Teletype equipment to be read for decryption The standard KL7 had no ability to punch tapes A variant of the KL7 the KL47 could also punch paper tape for direct input to teleprinters 產品詳情 每個轉子有 36 個觸點。 To establish a new encryption setting operators would select a rotor and place it in a plastic outer ring at a certain offset The ring and the offset to use for each position were specified in a printed key list This process would be repeated eight times until all rotor positions were filled Key settings were usually changed every day at midnight GMT The basket containing the rotors was removable and it was common to have a second basket and set of rotors allowing the rotors to be set up prior to key change The old basket could then be kept intact for most of the day to decode messages sent the previous day but received after midnight Rotor wiring was changed every 1 to 3 years The keyboard itself was a large sliding switch also called permutor board A signal coming from a letter key went through the rotors back to the permutor board to continue to the printer The KL7 was nonreciprocal Therefore depending on the Encipher or Decipher position of the permutor board the direction of the signal through the rotors was changed The rotor basket had two sets of connectors two with 26 pins and two with 10 pins at each end that mated with the main assembly Both 26 pin connectors were connected to the keyboard to enable the switching of the signal direction through the rotors Both 10 pin connectors on each side were hardwired with each other If a signal that entered on one of the 26 pins left the rotor pack on one of these 10 pins that signal was redirected back into the rotors on the entry side to perform a new pass through the rotors This loopback the socalled reentry created complex scrambling of the signal and could result in multiple passes through the rotor pack depending on the current state of the rotor wiring There was also a switch pileup under each movable rotor that was operated by cams on its plastic outer ring Different outer rings had different arrangements of cams The circuitry of the switches controlled solenoids which in turn enabled the movement of the rotors The combination of cam rings and the controlling of a rotor by several switches created a most complex and irregular stepping The exact wiring between switches and solenoids is still classified The KL7 was largely replaced by electronic systems such as the KW26 ROMULUS and the KW37 JASON in the 1970s but KL7s were kept in service as backups and for special uses In 1967 when the US Navy sailor John Anthony Walker walked into the embassy of the Soviet Union in Washington DC seeking employment as a spy he carried with him a copy of a key list for the KL47 KL7s were compromised at other times as well A unit captured by North Vietnam is on display at NSAs National Cryptologic Museum The KL7 was withdrawn from service in June 1983 and Canadas last KL7encrypted message was sent on June 30 1983 after 27 years of service The successor to the KL7 was the KL51 an offline paper tape encryption system that used digital electronics instead of rotors 參見 NSA encryption systems Typex Enigma 註釋 Britannica 2005 Proc 2005 differs saying that after the Walker family spy ring was exposed in the mid1980s 1985immediately all KL7s were withdrawn from service 參考 來源 Jerry Procs page on the KL7 retrieved 20120828 NSA Crypto Almanac 50th Anniversary The development of the AFSAM7 retrieved February 27 2011 Technical details and history of the TSECKL7 from Dirk Rijmenants Cipher Machines Cryptology retrieved February 27 2011 Patent for Rotor Reentry by Albert W Small filed 1944 from Free Patents Online retrieved February 27 2011 Cryptology Encyclopædia Britannica Retrieved 22 June 2005 from Encyclopædia Britannica Online Card attached to KL51 on display at the National Cryptologic Museum 2005 外部連結 TSECKL7 with detailed information and many images on the Crypto Museum website Accurate TSECKL7 Simulator Windows on Dirk Rijmenants Cipher Machines Cryptology Accurate TSECKL7 Simulator Java platformindependent released by MIT on Crypto Museum website Category 加密裝置