From Jefferson’s wheels to the unbreakable SIGABA — the wider world of cryptography
Beyond Enigma and Colossus lies a rich lineage of cipher machines stretching from the American Revolution to the Cold War. These devices — spinning wooden discs, clicking rotors, whirring pin-wheels — shaped the secret history of diplomacy and warfare. Some were broken spectacularly; one was never cracked at all.
The mechanical roots of modern cryptography, from Enlightenment-era ingenuity to the dawn of electric cipher machines.
Thomas Jefferson’s 26-disc cipher device. Rotate wooden discs to set plaintext, then read ciphertext from any other row. See how the recipient reverses the process.
The first electric rotor cipher machine. Type letters, trace the signal through internal wiring, and watch the rotor step — the invention that inspired Enigma.
The great cipher machines of the Second World War — devices that guarded the most critical secrets of every major power.
Japan’s diplomatic cipher with telephone stepping switches instead of rotors. Explore the 6-20 split and how Friedman’s team broke it without ever seeing the machine.
America’s unbroken WWII cipher. 15 rotors (5 cipher, 5 control, 5 index) create irregular stepping that no enemy ever cracked. Trace the signal through all three rotor banks.
Britain’s typewriter cipher machine with 5 rotors and a plugboard. Unlike Enigma’s lampboard, Typex prints encrypted output on paper tape. See the Combined Cipher Machine link to SIGABA.
The portable field cipher carried by front-line troops. Six pin-wheels of different sizes drive a lug cage that performs mechanical encryption. Set pins, type messages, watch the drum turn.