A columnar transposition, also known as a row-column transpose, is a very simple cipher to perform by hand. First, you write your message in columns. Then, you just rearrange the columns. For example.

In a prison, there are P prisoners. The prison is about to close, so the prison director proposes a game to the prisoners. In a room, P boxes numbered from 1 to P will be placed in a random order.

We all have secrets to keep. Those secrets could be personal dirt we want to keep from others, or they could be something as mundane as our credit card numbers or medical histories. But all of us have ...

It’s been a couple of Math Mondays since we last looked at columnar transposition ciphers, so let’s jump back in. In the It’s been a couple of Math Mondays since we last looked at columnar ...