Can you solve some of the most complicated cryptographic puzzles in the world?

The UK's Government Communication Headquarters (GCHQ) are some of the best code breakers in the world. Think you have what it takes to be a cryptanalyst? Find out here.

Image: GCHQ/Penguin Books

Let's start simple: If one person is lonely, and two are a network, how many people would you need to be threatening?

How about this: BAGG is to William the Conqueror as BEJC is to whom?

If you figured those answers out quickly you might just have the skills to match some of the top code-cracking minds in the world. The GCHQ has an illustrious history of employing talented hackers, master puzzle smiths, engineering geniuses, and cryptography masterminds. Its new book gives you the chance to see if you have what it takes.

What is the GCHQ?

The GCHQ came into being after World War I when the government realized it needed an agency devoted to code breaking during peacetime.

The GCHQ has employed the likes of Alan Turing, was fundamental in breaking the Nazi Enigma encryption device, and even invented RSA encryption that's still in use today.

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In 2015 the GCHQ director released a multi-part puzzle along with yearly Christmas cards. In the end no one was able to solve the entire puzzle, but it gave rise to an idea: Why not put out an entire book of puzzles?

The most difficult book in the world?

Every single puzzle in the GCHQ Puzzle Book is designed by a code breaker at the agency, and that means it's not going to be easy.

The first chapter features some simple puzzles to lure you into a false sense of your own skill, then quickly ramps up the challenge. I was easily able to solve the second puzzle (what is missing: Picture Menace, Khan Clones, * *, Home Hope, Frontier Back), but by the end of the easy chapter I was lost.

That's not to say the book is too difficult--other readers will surely be able to solve the puzzles that left me scratching my head. I have no qualms about admitting my lack of puzzle solving skills.

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That first chapter of simple puzzles generally requires one specialized bit of knowledge, but the rest of the book requires crossing disciplines to reach an answer. For an extra hard challenge there's even a section of puzzles that don't have instructions--it's up to you to figure them out.

When it comes down to it some people are incredibly gifted code crackers and puzzle solvers. There's a certain kind of abstract thought that goes into solving many of the puzzles in this book and it's something that requires a lot of practice or natural skill.

If you fancy yourself someone with talent for hacking, cracking codes, securing systems, or building the unbreakable the GCHQ Puzzle Book is a must read. Just don't get too upset when it brings you back down to earth.

Want to see what you're capable of? Check out the gallery that features some of the puzzles from this book. The first person to submit all the correct answers wins a copy of The GCHQ Puzzle Book!

Solutions to puzzles contained in this article

The first puzzle requires you to look inside the words: one person is lONEly and two people are a neTWOrk, now look at threatening: It contains the number ten, which is the answer.

This puzzle involves substituting numbers for letters. If you subtract one from every letter's position in the alphabet, BAGG=1066, which is the year William the Conqueror took the throne of England. Using the same rules BEJC=1492, which is the year Columbus landed in the Americas, making him the answer.

The puzzle mentioned as the second puzzle in the book consists of Star Trek and Star Wars movie titles in numeric sequence. That makes the third pair Spock Sith.

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