In the two decades prior to World War II, Edward Hebern (1869-1952) was the first American inventor to make a very significant contribution to cipher machine development. His machines were the first to embody the wired rotor principle of encipherment. Hebern continued to design and build electro-mechanical rotor machines until the eve of World War II. For various reasons, he never managed to secure a large scale contract with the U.S. Government.

This machine, featured at the National Cryptologic Museum, was built before 1920 in Hebern's Oakland, California machine shop. The early model had only one rotor. In order to decipher a message, the rotor would be removed and turned around. Later models added more rotors. (Photo by Mark Pellegrini)

Displayed below is Hebern's first rotor machine. Employing a single rotor and beautifully made of solid brass, the machine worked in conjunction with a Remington Model 10 electric typewriter for hard copy
as shown in Hebern's first patent 1,510,441. Part of the crypto machine's mechanism was driven electrically and part by a falling weight and pulley. (Item 52 below, inside 53)