U.S. TSEC/KL-7 Simulator v5.0

 Dirk Rijmenants
This software is an accurate simulation of the KL-7 cipher machine, codenamed ADONIS or POLLUX. The KL-7 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 sounds are 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 to keep its history alive. The simulator comes with an extensive 20 page manual PDF Format that includes the use of the simulator, the KL-7's technical details, its history and sample messages.

The simulator is based on the most recent information on the KL-7 and developed in collaboration with Crypto Museum. It's principles of operation and technical details are known but 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 exactly the same cryptographic principles as the real KL-7 but consequently uses its own rotor wiring.

More information is found on my KL-7 webpage. All feedback, comments or questions are most welcome by e-mail or by visiting the Guestbook.

Runs on all Windows™ versions and on MAC with CrossOver, Parallels Desktop or WINE. There's also a Java version available.

Download the simulator

Download the TSEC/KL-7 Simulator v5.0.1 (Zip 2.69 MB) Please check the readme file before installation.

Download Java KL-7 Simulator v5.0 (5,99 MB) Uri Blumenthal from MIT Lincoln Laboratory wrote a JAVA version of my KL-7 sim (requires Java Version 8)

Check the integrity of the downloaded software with SHA-256.

Discover also my Enigma, US M-209 and Hagelin BC-52 cipher machine Simulators!

Updates for this Simulator

Help File Edition 2022-01 PDF Format This version is not included in the installation file! To add to the installed KL-7 Sim, right-click link and save manual in KL-7 installation folder (usually "C:\Program Files (x86)\KL-7") without changing the file name. This file contains the manual and updated contact information and links.

More About KL-7 on this Site

The KL-7 on SIGINT Chatter (opens in new tab)

Web Analytics Made Easy -

Dirk Rijmenants 2004. Last changes: 21 February 2022