Rubic-Cube-Challenge-bar

A Rubik’s Cube can be used to implement a low-tech encryption method. But is it secure? Here’s a challenge for my readers to solve.

Cards-bar

Designing a secure manual encryption algorithm is a challenge. Some cryptographers have developed ciphers that require a deck of playing cards. The best-known one of this kind is Bruce Schneier’s Solitaire. Today, I am going to introduce another one: Talon by Aaron Toponce.

Crypto-Number-Sheet-bar

The crypto number table is a simple, yet far from trivial cipher. Can you break a cryptogram I have created with this method?

LC4-bar

LC4 is a cipher that can be computed by hand. According to its creator, it is both secure and easy to use. Is LC4 better than other low-tech ciphers I have introduced on this blog?

Mathias-Sandorf-bar

In the novel Mathias Sandorf by Jules Verne the use of a Turning Grille is described. Does a reader know other encrypted messages of this kind?

Bruce-Kallick-Handycipher-bar

Designing a secure and convenient encryption algorithm that doesn’t require a computer program or a machine is quite a challenge. The Handycipher is an interesting method of this kind.