He wrote a trilogy of books called Military Cryptanalytics covering code breaking in 1977 ... with some examples of hard-to-solve crypto puzzles. One key part of the book, apparently, is ...

With a fresh puzzle to mark its debut on the online ... they can solve the problem if they are interested in a career in code-breaking. Hidden within the image are 13 elements that represent ...

The key to unlocking the puzzle is identifying Samuel, Louis and Ludwik. In this case, we need to find a common link between them. They are all pioneers in the world of language and code ...

CLUE: The key to unlocking the puzzle is identifying Samuel ... you can join the social media conversation on the GCHQ code-breaker challenge using hashtag #GCHQpuzzlebook.