AT&T Tech Channel

About this video

In 1917, AT&T engineer Gilbert Vernam invents a cipher machine to encrypt transatlantic telegraph messsages sent by the War Department to United States troop commanders in Europe during WWI. The system, which is modified by the Army Signal Corps, is later proved to be unbreakable. The so-called One Time Pad Cipher is the first example of online encryption.

Some images and video courtesy of the

AT&T archive videos and imagery courtesy of the AT&T Archives and History Center.

Release date: 10/12/2009