For many years GCHQ have delivered a Christmas Challenge to delight, frustrate and amuse its friends and enemies alike. This year’s competition was launched today, and you can find it on their website at
https://www.gchq.gov.uk/files/gchq%20christmas%20challenge%202025.pdf
For those of you who are looking for something a little harder (as in: a LOT harder) you could take a look at the original challenge posted by the Director in 2015. That page contains the first part of the challenge and you need to solve it to reveal the next and so on. There is also a link to all the solutions on that page, but I would recommend NOT clicking on it if you want to try the puzzles for yourself.
Have fun,
