"On This Date in History" Calendar
1875: Charles Wheatstone Died.
19 October 1875: Charles Wheatstone, inventor of the Playfair Cipher and the Wheatstone Cryptograph, died. The Playfair Cipher is a manual symmetric encryption technique and was the first literal digraph substitution cipher. The Wheatstone Cryptograph was a pre WW I-era cipher device used extensively by the British during WW I. Learn more about it HERE.