Director's Christmas Puzzle - The Answers
This year, along with his traditional Christmas cards, Director GCHQ Robert Hannigan included a brain-teasing puzzle that exercised the grey matter of participants over the holiday season.
The card, which featured the 'Adoration of the Shepherds' by a pupil of Rembrandt, included traditional Christmas greetings from Director on behalf of the department. However, unlike previous years, the 2015 card contained a grid-shading puzzle and instructions on how it should be completed. By solving this first puzzle players created an image that lead to a series of increasingly complex challenges.
Once all stages were unlocked and completed successfully, players were invited to submit their answer via a given GCHQ email address by 31 January 2016.
The answers are now available for you to check how many you managed to work out. It also includes explanations from the puzzle-setters that should hopefully make things a little clearer ... or not.
Alongside the teasing puzzle, Director encouraged participants to donate to his chosen charity, the NSPCC.
Thank you to everyone who took part; we hope you enjoyed the challenge!