Arthur Scherbius, German electrical engineer, invented the Enigma machine (born 1878)

Arthur Scherbius was a German electrical engineer who invented the mechanical cipher Enigma machine. He patented the invention and later sold the machine under the brand name Enigma.

The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the German military. The Enigma machine was considered so secure that it was used to encipher the most top-secret messages.

May 13 is the 133rd day of the year in the Gregorian calendar; 232 days remain until the end of the year.