Britain’s intelligence service is seeking spies for Christmas. Specifically, a highly cryptographic Christmas card was sent out by the Government Communications Headquarters (GCHQ) that asks people to fill in a grid puzzle by shading in little squares to reveal a picture, which leads to a set of increasingly complex challenges.

But it was far from the first test of its kind issued by an intelligence agency… Try the following tests and see if you can crack the solution and make it into the spy world.

If you can crack that, then maybe you can use your skills to combat terrorism and cyber threats!

Some people, states The Register, managed to find the final webpage using a site: command in Google.

In 2013, GCHQ released another internet competition called Can you Find It? where they had to decode four lines.

Here’s a quiz by the FBI. Can you solve it?

An MI5 recruitment puzzles. Can you piece these together?

Crack this code and get a job at the US National Security Agency: