M-209

The M-209

In cryptography, the M-209, designated CSP-1500 by the United States Navy (C-38 by the manufacturer) is a portable, mechanical cipher machine used by the US military primarily in World War II, though it remained in active use through the Korean War. The M-209 was designed by Swedish cryptographer Boris Hagelin in response to a request for such a portable cipher machine, and was an improvement of an earlier machine, the C-36.

The M-209 is about the size of a lunchbox, in its final form measuring 3+14 by 5+12 by 7 inches (83 mm × 140 mm × 178 mm) and weighing 6 pounds (2.7 kg) (plus 1 pound (0.45 kg) for the case).[1] It represented a brilliant achievement for pre-electronic technology. It was a rotor machine similar to a telecipher machine, such as the Lorenz cipher and the Geheimfernschreiber.

  1. ^ "Dossier : Le Converter M209: chiffreur - déchiffreur". us-militaria.com. 1 January 2014. Archived from the original on 1 January 2014.{{cite web}}: CS1 maint: bot: original URL status unknown (link)