Miao Ai

Publication Date

Spring 2012

Degree Type

Master's Project


Computer Science


In this project, web-based visual simulators have been implemented for three classic rotor cipher machines: Enigma, Typex, and Sigaba. Enigma was used by Germany during World War II, while Typex is a British cipher that was based on the commercial version of the Enigma. Sigaba is a relatively complex machine that was used by the Americans during the 1940s and into the 1950s. Sigaba is the most secure of the three ciphers, there was no successful attack on Sigaba during its service lifetime. Our web-based visual simulators are functionally equivalent to the actual electro- mechanical machines. Each simulator allows the user to initialize the key and encrypt or decrypt. Also, each simulator provides a web-based “play station” that allows the user to understand how these classic ciphers work by observing their internal operations when encrypting and decrypting. These simulators do not require any installation, and users can access the simulators provided they have access to the Internet.