- A fully operational Swiss Enigma ("k") cipher machine. Berlin, Germany, Heimsoeth und Rinke, c 1939.
- ALUMINUM, METAL, GLASS, POWER SOURCE
3-rotor Swiss ("K") model Enigma cipher machine, serial number K 767, complete with 3 aluminum rotors (I, II, & III) and Umkehrwalze (reflector) all with matching serial numbers (K 795), reflector and rotors with 26 positions for each letter of the alphabet; control panel with standard raised "QWERTZ" keyboard of 26 metal and glass keys in white on black backgrounds, combined rotor cover and light panel with letters A-Z, metal label reading "K 767", power source dial switch, and two nodes for connection to external power source, panel lifting to reveal 26 light bulbs, rotor & reflector compartment, and battery compartment. Housed together with attached external lamp panel with letters A-Z in the original extra-wide oak carrying case (15 x 11½ x 6 in.) with leather handle, lid of case with 10 spare bulbs, green contrast filter, and original paper instruction pamphlet printed in French & German. Together with original external power supply in its original oak case (7¾ x 4½ x 5¼ in.) with leather handle.
A VERY FINE, COMPLETE, AND FULLY OPERATIONAL EXAMPLE OF THE MOST FAMOUS ENIGMA K CIPHER MACHINE VARIANT, THE SO-CALLED "SWISS-K." The Enigma K was an improved version of the 3-rotor Enigma D, which was supplied with an Umkehrwalze
(reflector) and three rotors, all with 26 positions labelled with the letters of the alphabet (a convention that would also be used on the later 4-rotor "M4" Enigma). Developments started in 1927 to create improved versions of the commercial Enigma D, and apart from a few manufacturing modifications, the K is nearly identical to the D. Many Enigma K machines were built for German users, but they were also sold to foreign users. Modified versions were used during the Spanish Civil War from 1936-1939, and it was used by both the Swiss Army and the Italian Supermarina
(Navy) during WWII.
The Swiss variant of the Enigma K came with an external lamp panel for an extra layer of security, as well as an external power supply. The Swiss re-wired the rotors and even modified the rotor turn-over system on some machines. While the Enigma machines were manufactured in Germany, the external light panel and the custom extra-wide cases were manufactured in Switzerland. In 1940 the Swiss discovered that the French had intercepted some of their Enigma traffic. In response, the Swiss altered the stepping mechanism in their Enigmas, making the rightmost rotor stationary, and having the middle rotor step with every key press, while the reflector and left-most rotor following standard Enigma stepping. Despite this measure, along with regular re-wiring of their machines, allied code-breakers continued to intercept Swiss Enigma traffic. The Swiss had known since 1939 that the Germans were intercepting their Enigma traffic as well, and so the Swiss decided to develop their own machine known as the NEMA (Neue Machine).