Nadael Guindy’s Cryptographic Gadget Brings Leon Alberti’s Cipher Discs to the Arduino UNO

Maker Nadael Guindy has introduced a basic of cryptography updated — by constructing an Alberti cipher disc powered by an Arduino UNO board.

“In 1467, the quintessential ‘Renaissance Man’ Leon Battista Alberti changed the world of secrets forever,” Guindy explains by the use of background to the mission. “Alberti invented what is now considered the world’s first polyalphabetic cipher: a mechanical device featuring two concentric disks that allowed for encryption far more sophisticated than the simple substitution ciphers that had come before it. By translating Alberti’s physical brass rings into an Arduino-powered digital system, this project explores how a tool designed over half a millennium ago can still be evolved using modern electronics.”

A substitution cipher is a option to take a plain-text message and defend it towards informal statement: take every letter and swap it for a unique letter, or for symbols or numbers. Without understanding which letters have been swapped, it is tough to learn the message — although not not possible, significantly when all letters have been swapped by the identical variety of locations within the alphabet. A polyaphabetic cipher goes a step past a easy substitution cypher, with Alberti’s brass disc implementation being one of many first recorded.

Guindy’s recreation borrows an analogous structure to the dual-disc brass of the unique, although that is purely an aesthetic affectation: the exhausting work is carried out in an Arduino UNO, operating a digital Alberti cipher and displaying the outcome on an OLED display screen. Two knobs present a option to management the cipher: a potentiometer for “coarse” base shift choice, and a rotary encoder for choosing particular person letters.

“To make the encryption incredibly secure, the device doesn’t just use one static shift; it uses a non-linear dynamic key,” Guindy explains. “This means that for every few letters you type, the ‘inner disc’ automatically shifts in a complex, constant pattern based on a mathematical formula. Because the key changes as you go, the same letter will be represented by different characters throughout the message, making it nearly impossible for a codebreaker to spot a pattern without knowing the secret starting position!”

The mission is documented in full, together with wiring diagrams and supply code, on Instructables.