Answers To GCHQ Christmas Puzzle Revealed

GCHQ has revealed the answers to the head-scratching puzzle in director Robert Hannigan’s Christmas card.

Hundreds of thousands of amateur cryptographers took on the challenge, with around 30,000 (5%) getting to the final stage - but only three people came close to cracking it.

The three winners, all men, battled through five rounds and beat 600,000 people to come closest to fully solving the series of challenges.

One of them, David McBryan, 41, from Edinburgh, told Sky News: “In total, I spent the best part of three days on it.

“But the difficult bit is definitely the last stage because you don’t know when you’re finished.

“You don’t know how many answers they’re looking for. You don’t know what form they take, so it’s very easy to waste a lot of time still looking for more.”

The two other winners were Wim Hulpia, 40, from Lovendegem, Belgium, and American-born Kelley Kirklin, 54, who lives in London.

GCHQ, one of Britain’s intelligence and security agencies, says it was “delighted” with the public’s response.

It said many people worked in virtual teams over various web forums to tackle the questions together.

Some syndicates even developed small computer programmes to test possible mathematical combinations and reach a solution more quickly.

GCHQ said the Sum in Question 5 caused the most confusion among players.

Almost everyone got the answer xiv, and quite a few got two additional answers l and xx based on interpreting the x as a multiplication sign.

However, no-one found the four additional intended answers involving further reinterpretation of x as a multiplication sign.

GCHQ said the Manifold Agreement appears to have been solved without anyone spotting the idea of writing the tiles into the square at an angle.

Looter was many people’s favourite, particularly the way the title LOOTER relates both to the answer and also to LOTR = Lord of the Rings using the theme of the rest of the puzzle.

In the Crossword there was a typo in the grid - 27 across was labelled 17 by mistake, which apparently led to a great deal of theorising about the significance of 17 vs 27. GCHQ has apologised for this.

In the Cipher some participants worked out the ternary coding but could not solve the resulting substitution.

There was no overall theme to the Part 5 answers. GCHQ says this was intentional as it “wanted it to be difficult for players to tell when they had finished, and to reduce the likelihood that a full solution would be published”.

Click here for the full set of answers.