Scytale

Wrap one of the strips around the first pole. Read the letters across the pole. Can you see a message? If not, try the other two poles.

Can you decrypt all three messages?

Is it possible to read a message without a pole? What other ways can you find?

You may have seen codes that change the letters of your message into shapes or symbols. These types of codes are called substitution ciphers.

But another way to send a code is to jumble up the order of the letters – making an anagram. These types of codes are called transposition ciphers.

For example, one way to mix up the letters is to write down every second letter before going back to the start and writing down the remaining letters.

So, the word PEANUT becomes PAUENT.

Alternatively, we could write down every third letter, or every fourth letter.

The size of the gap is called the key, and it can anything you choose. But it is important that your friend knows what the key is so they can decode your messages.