Jump to Main ContentJump to Primary Navigation
Top

Can you solve GCHQ's Christmas card puzzle?

santa.jpg

When they aren't busy riffling through your deleted emails for terrorism buzz phrases, the sleuths at GCHQ love nothing more than a good puzzle.

really good puzzle. The sort of thing that makes the cryptic crossword look like a colour-by-numbers job.

To demonstrate their softer side, the agency has revealed its 2015 Christmas Card - whose festive message will only be revealed once you've deciphered a code.

"In this type of grid-shading puzzle, each square is either black or white," explains GCHQ. "Some of the black squares have already been filled in for you. Each row or column is labelled with a string of numbers. The numbers indicate the length of all consecutive runs of black squares, and are displayed in the order that the runs appear in that line. For example, a label '2 1 6' indicates sets of two, one and six black squares, each of which will have at least one white square separating them."

But that's just the start of the 'fun' - revealing the image "leads to a series of increasingly complex challenges". 

Should you enjoy the puzzle, GCHQ is inviting you to pass on your Christmas joy by donating to the NSPCC.

Let us know how you get on...

gchq

(Images: Shutterstock, GCHQ)

[Via: Mental Floss]

Related

facebook1.jpg

Facebook unveils its 2015 Year In Review

russell1.jpg

Exclusive: Read Russell Brand's open letter to Father Christmas

DeckTheHalls.jpg

7 houses whose Christmas lights are twenty times crazier than yours

stay-another-day.PNG

Can you guess these 14 Christmas songs from the emojis?

2003_elf_002.jpg

Quiz: Can you guess the Christmas movie from the pixelated screenshot

rexfeatures_824781a.jpg

A Man's guide to Christmas

Comments

More

Super Mario in Grand Theft Auto is weird and awesome

Who would've thought Mario would get into a knife fight in a park?

by Jamie Carson
18 Jan 2017

The only Vines worth preserving

The most important cultural artefacts of our time

by Tristan Cross
17 Jan 2017

Hurrah: The Nintendo Switch now has a price and release date

Here's everything you need to know about the new console

by Tom Fordy
13 Jan 2017

The best underwater photographs of 2016 are staggeringly beautiful

Aquatic snaps that made a splash

by Dave Fawbert
12 Jan 2017

Using Google Maps actually does ruin your sense of direction

"Make a U-turn where possible"

by Dave Fawbert
11 Jan 2017

Netflix releases 8-bit game featuring Narcos and Stranger Things

Goodbye, productivity.

by Emily Badiozzaman
10 Jan 2017

The original Game Boy is coming back

Time to dust off your Pokemon Red & Blue cartridges

by Jamie Carson
10 Jan 2017

Watch Steve Jobs launch first iPhone 10 years ago

Today marks 10 years since Steve Jobs presented the world with this iconic product, but it could have been so different

09 Jan 2017

The best gadgets to launch at the biggest tech conference in the world

Christmas 2017 can't come early enough

by Joe Ellison
05 Jan 2017

This is why hitting the snooze button is bad for your health

If you snooze, you really do lose

03 Jan 2017