Escape Game History: 3 Ciphers Once Considered “Unbreakable”

The Enigma Machine at the National Museum of Scotland (Photo: Nachosan CC-BY 3.0)

If there’s one thing you’ll find in every escape room you play, it’s some sort of code that you’ll have to break. We’re definitely cryptography nerds here at Krakit Vancouver Escape Game, and that’s why we’re so fascinated with the ciphers that no one has been able to solve (see here, here, and here for some of our faves).

However, eventually, every code will get cracked—it may just take several hundred years, that’s all.

Below are three ciphers that were once considered unsolvable, but no more. Cryptanalysis wins!

Enigma, created: 1918

The German electrical engineer Arthur Scherbius patented his Enigma Machine, a mechanical cipher machine, in 1918, and it was soon adopted by German military forces. What made it so famously unbreakable is that the Enigma Machine uses electrical signals to concoct a new code every time a key is pressed, so it never uses the same code twice.

You can see why it was considered uncrackable.

Nevertheless, Enigma was broken by the WWII codebreakers of Bletchley Park, headed up by Alan Turing. Though it certainly it wasn’t an easy task, that’s for sure.

Vigenère Autokey, created: 1586

While the Enigma remained unbreakable for over 30 years, it’s nothing compared to the Vigenère Autokey’s 300 years. It was so safe a code, it was even nicknamed le chiffre indéchiffrable, or “the indecipherable cipher” to us English speakers.

The Vigenère uses polyalphabetic substitution (that means it really mixes the alphabet up), which makes it easy to use but really hard to break. This is in fact the same principle Enigma would use many years later.

However, in 1855, the inventor Charles Babbage came along and solved the Vigenère cipher for the English during the Crimean War. Because Babbage didn’t publish his work, the cipher continued to be used until 1863(!), when Friedrich Kasiski published his attack, rendering the Vigenère useless.

The Alberti Cipher, created: 1467

An even older once “unbreakable” code is the Alberti Cipher. This code was created by Leon Battista Alberti, and is the oldest known polyalphabetic cipher. (Are you seeing a pattern here?) Like the Enigma and the Vigenère, the Alberti Cipher uses metal discs that rotate to create a new code with every spin.

Alberti was dead certain his cipher was unbreakable, and although it took several centuries to prove him wrong, we now know that polyalphabetic ciphers can—and will eventually—be broken.

Try your own hand at codebreaking in one of our four escape games: http://bookeo.com/krakit.