The School Code Challenge is based on a similar competition that GCHQ (The UK digital spy agency) are running. My clues will however be a little more accessible! I have created a number of codes that need to be broken. Each code will give a password. When you crack the code, follow the link and enter the password to access the next code. There are five codes in each level. After completing the final code there will be a submission box where you can enter you name. I will put up a leaderboard of all the successful entrants.

There are now 3 levels of codes – Level 1 is designed for KS3 and KS4 students (11-16).  Level 2 is designed for KS4 (14-16).  Level 3 is designed for post 16 students (A level and IB).   Can you break all levels?  Scroll down to see a leaderboard of students who have completed this challenge!

Level 1 Code Number 1:

code 1

Level 2 Code Number 1:



Level 3 Code Number 1:


Level 1 Code Number 1 Information:

1) A Roman emperor may help you discover the method.
2) Frequency analysis may also help you – what is the most common letter in the English alphabet?

When you have solved this puzzle click here to enter you password and gain access to the second code.

Level 2 Code Number 1 Information:

Actually, this is quite a nice gentle start to Level 2 – but don’t worry, they do get harder!  When you’ve cracked it, click here for the second code.

Level 3 Code Number 1 Information:

Binary strings are used as a method of transmitting data across large distances (Voyager 1 used this method to transmit pictures from Jupiter in 1979 – a massive 600 million miles away).  Make a rectangular grid by factorising the length of the binary string above into prime factors to reveal a secret message.  When you’ve solved it write the password (in word(s)) here. Warning – this level is not for the faint hearted!

Leaderboard: Click here (and scroll down) to see a list of students who have completed this challenge!


If you are a teacher and would like to run this as an in-house school competition then if you contact me I will send out the full questions, answers and code breaking pack (with student worksheets and murder mysteries etc). It is also available on TES here.

For more code breaking content, check out:

Crack the Code to Become a Spy : Information about the current GCHQ competition – with prizes to be won for those who can solve the puzzle.

Cracking Codes Lesson. An example of 2 double period lessons on code breaking

NASA, Aliens and Binary Codes from the Stars. A post about how pictures can be transmitted across millions of miles using binary strings.