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 ...

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 ...

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 ...

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.