A new Christmas puzzle has been released by GCHQ.
The brainteaser comes in Christmas card form and members of the public need to break the code to decipher the message inside.
Colleagues at the organisation in Cheltenham, responsible for intelligence and security across the country, have put their minds together to create the annual puzzle, reports Gloucestershire Live .
The GCHQ Christmas puzzle combines a code-breaking message and a classic Sudoku theme.
So can you work it out?
On the company's website some tips and clues have been shared to help people solve it.
The first is to download and print the 2019 Christmas puzzle.
Then have a go at working out the message that snakes its way through the snowflake.
Once you've done that, colour in the snowflake so that each circle of six hexagons surrounding a grey hexagon uses each of the six colours once.
The website also adds that to work out the significance of the coloured snowflakes you might need a ruler.
A GCHQ spokesman said: "Using GCHQ’s great mix of minds, which has helped to keep the country safe for more than 100 years, we’re wishing people a Happy Christmas in the only way we know how with this festive conundrum."
Check out Director Jeremy Fleming's Christmas card puzzle here.
Tweet @GCHQ with your answer and what the hidden message is.
