This software is an accurate simulation of the KL-7 Cipher Machine. The KL-7, codenamed ADONIS or POLLUX, was an off-line rotor cipher machine, developed in the late 1940's by the American Armed Forces Security Agency (AFSA) and introduced by the newly formed National Security Agency (NSA) in 1952. The KL-7 served in the United States and several NATO countries until 1983 (more info on the TSEC/KL-7 webpage).
The KL-7 simulator provides authentic handling with its hands-on approach. All switches, buttons and even the sound function exactly like the real KL-7. Its rotor and cage wiring are fully customizable. With most surviving KL-7s sanitized, this simulator is the only remaining way to actually work with this beautiful machine and the simulator serves as an attempt to keep this machine and its history alive. The simulator comes with an extensive 19 page manual that includes the use of the simulator, the KL-7's technical details, its history and sample messages.
The development of this simulator is based on publicly available information on the KL-7. It's principles of operation and most of the technical details are known. However, the internal wiring of the ciphering rotors and the stepping unit, which are considered part of the secret key settings, are still classified. The KL-7 simulator operates with the same cryptographic principles as the real KL-7 but consequently uses its own rotor and stepping wiring. Discover all technical details and history on my KL-7 webpage. All feedback, comments or questions are most welcome by e-mail or by visiting the Guestbook.
Runs on Windows™ 98/ME/2000/XP/Vista/Win7/Win 8 and on MAC and Linux with Parallels Desktop or WINE (open source).
Download the simulator
Download the TSEC/KL-7 Simulator v4.1.2 (Zip
Download JAVA KL-7 Simulator v3.9 Uri Blumenthal from MIT Lincoln Laboratory has written a JAVA version of the KL-7 simulator for non-Windows users. You can download it as jar file from my Dropbox
Updates for this Simulator
Please uninstall any previous version through configuration screen/software and remove 'KL-7' before installing the new version!
v4.1.2 (25 Mar 11) The KL-7 sim is now updated with the most recent details about its principle of operation, the stepping unit and the mode switch. The sim now produces realistic sounds, sampled from a real KL-7 in operation. Additionally, the manual is expanded with recently by NSA declassified information on the developement of the KL-7. Warning: this updated version v4.1 is cryptographically not compatible with earlier versions!
More About the KL-7