Secret Codes

What your child learns

• Caesar’s shift cipher and the code wheel
• Frequency analysis: the most common letter
• Keyword ciphers
• Patterns, alphabets and careful checking

How to play

The wheel shows each plain letter over its code letter. Turn it to the key, then tap the letters to decode the word. Without a key, look at the letter counts and turn the wheel until the message reads.

Levels

1. Level 1Decode with a given key.
2. Level 2Crack a message by counting letters.
3. Level 3Decode a keyword code.

A tip for parents

Send each other coded notes at home with a shift of your choice. Can your child crack yours without the key?

Works on phones, tablets and computers, with nothing to install. No ads and no tracking.