C-36 (cipher machine)

The C-35 and C-36 were cipher machines designed by Swedish cryptographer Boris Hagelin in the 1930s.

In 1934, the French military approached Hagelin to design a printing, pocket-size cipher machine; Hagelin carved a piece of wood to outline the dimensions of a machine that would fit into a pocket.

He adapted one of his previous inventions from three years earlier: an adding device designed for use in vending machines, and combined it with the pinwheel mechanism from a late 1920s cipher machine Hagelin had developed.

Completely mechanical, the C-35 machine measured 150 by 115 by 50 millimetres (6 in × 4.5 in × 2 in), and weighed less than 1.5 kilograms (3 lb).

The C-362 revision included a few other improvements, most notably movable lugs instead of fixed.