About: Syko Cipher Device

The SYKO cipher device was a compact British cipher apparatus in use during World War II. It was invented and patented by Morgan O'Brien before the war. O'Brien developed a sophisticated cipher typewriter, which was complex and delicate, but then came up with the relatively simple device adopted by the military that was known the SYKO. Although the German crypt analysts managed to break the SYKO code, it remained in use for much of the war as a quick method for low-level encoding of radio traffic, particularly from aircraft. Code breaking took considerable time plus a sufficient sample of messages, and for certain classes of radio traffic (such as an aircraft's position) decoded information that became available many hours later was of little value.