Cryptologic History

"On This Date in Cryptologic History" Calendar

1875: Charles Wheatstone Died.

Sunday, October 19, 2025

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.

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