If you would like to support the site then have a look at the following resources you can purchase:

1. The 2025 FOBISIA Code Breaking Pack.

This is a 53 page pdf with all the codes and solutions for the 2025 FOBISIA Code Breaking competition. The code levels included are Level 1A, Level 1B, Level 2A, Level 2B, Level 3 and Level 4. Each of Levels 1-3 include 5-6 codes and Level 4 is a super challenging test of genius. Each code is on a separate page – making this excellent for gifted and talented activities, whole school maths code breaking and inter-schools challenge.

You can purchase this for $10 at this link here. (Note this is not an automatic download – I will send an email within 24 hours of purchase to the email provided).

2. The 2024 FOBISIA Code Breaking Pack.

This is a 48 page pdf with all the codes and solutions for the 2025 FOBISIA Code Breaking competition. The code levels included are Level 1A, Level 1B, Level 2A, Level 2B, Level 3 and Level 4. Each of Levels 1-3 include 5-6 codes and Level 4 is a super challenging test of genius. Each code is on a separate page – making this excellent for gifted and talented activities, whole school maths code breaking and inter-schools challenge.

You can purchase this for $10 at this link here. (Note this is not an automatic download – I will send an email within 24 hours of purchase to the email provided).

3. The Code breaking with Python Pack

This is a 17 page pdf which talks students through how crack 5 different codes using some Python coding techniques. This would be great for high achieving students who want to explore the links between coding and computing or as a cross-curricular activity between Maths and Computing.

You can purchase this for $8 at this link here. (Note this is not an automatic download – I will send an email within 24 hours of purchase to the email provided).

Top free resources

1) The Boxentriq site has a large number of code generators for Caesar shifts, transposition ciphers, pigpen, Vignere codes and more.  This is a great resource for generating and understanding a large number of codes. One of the best resources online.

2) CIMT Code resources – a fantastic resource for teachers with a large number of ready made worksheets and teacher notes on lots of different codes.

3) Khan Academy code breaking videos– a large number of short videos looking at both codes through history and more modern code methods.

4) Simon Singh’s Black Chamber is another excellent resource for code breaking methods – use computation methods to crack a host of codes.  You can also conduct frequency analysis here.  Simon Singh’s The Code Book is also an excellent read.

Other Resources:

1) Additional resources for creating Vignere codes

2) Additional resources for creating Semaphore codes

3) Morse Code generator

4) Nrich has a nice article about the history of codes and mathematics

5) Reverse text, flip text, flip wording and more here.

6) Learn how to use the One Time Pad – a favourite coding method of spies in the Second World War.