Challenge type: Secret Codes · Difficulty: ★★★★★ Super tricky · Code: Shift code
Pixel left Beep a secret note, but it’s written in a shift code. Can you work out what it says?
The secret message
TSDD
How the code works
This is a shift code, but we’re not telling you the shift! Every letter moved forward by the same number of places, somewhere between 1 and 25.
Code-breaker’s trick: try decoding just the first word with shift 1, then 2, then 3… When it turns into a real word, you’ve found the shift!
Need a hint?
The first word of the answer has 4 letters and starts with B.
Safety first: Secret codes are great fun with friends and family. But remember: never keep a secret from your grown-ups that makes you feel worried or uncomfortable.
For teachers and grown-ups
Skills practised: Algorithms, encoding and decoding, and logical reasoning (cryptography basics).
The big idea: A cipher is an algorithm. Knowing the method and the key lets you undo it.
Questions to ask:
- What does the key (the shift) do?
- How could you crack a shift code without knowing the key?
- Why are simple codes like this not safe for real secrets?
Take it further: Make the paper code wheel from our printables and send messages between groups.