Tactile Ciphers

One fun feature of classical ciphers is the opportunity to puzzle out the code in physical space.

For example: the scytale is a cipher tool dating back to the ancient Greeks. The encoded message is written on a long strip of parchment. This is then wrapped around a rod, the scytale itself. If the scytale is the correct thickness, the message is revealed by reading across.

If you know the trick, the code can be easily cracked brute force. But even if you don't know, there's a tactile element to a strip of parchment that invites you to play with it until it's cracked.

Same goes for the rail fence cipher, or various grille ciphers; once you bring these codes into a physical, tactile space, the human brain starts to think about them differently.

a lego Reihenschieber from Klaus Schmeh's own blog