KL-7 Cipher Machine

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.

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-7’s 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 20 page manual (view here ) 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, which is considered part of the secret key settings, is 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.

Runs on Windows™ 98/ME/2000/XP/Vista/Win7/Win 8/Win 10 and on MAC with Parallels Desktop or WINE on Linux.

Download KL-7 Simulator
Download Manual

For more detailed information on the KL-7 and other encryption machines visit the Cipher Machines and Cryptology page.

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