Cryptography

The long argument between hiding things and finding things — Caesar cipher to post-quantum standards.

8 posts· 404 BCE – 1795

• Jefferson's wheel cipher, or the invention the army made twice 1795
• Bellaso's cipher, or three centuries filed under the wrong name 1553
• Trithemius's Polygraphia: the abbot's grid that launched three centuries of polyalphabetic ciphers 1518
• Alberti's cipher disk: the wheel that broke frequency analysis 1467
• Al-Kindi's frequency analysis, or how counting letters broke every substitution cipher 850 CE
• The Kama Sutra cipher, or why secret writing was the forty-fourth art 400 CE
• The Caesar cipher, or how a shift of three kept Rome's orders from Gallic hands 54 BCE
• The scytale, or how Sparta encrypted its orders 404 BCE