The Amazon description:
If 3=T, 4=S, 5=P, 6=H, 7=H … what is 8?
What is the next letter in the sequence: M, V, E, M, J, S, U, ?
Which of the following words is the odd one out: CHAT, COMMENT, ELF, MANGER, PAIN, POUR?
GCHQ is a top-secret intelligence and security agency which recruits some of the very brightest minds. Over the years, their codebreakers have helped keep our country safe, from the Bletchley Park breakthroughs of WWII to the modern-day threat of cyberattack. So it comes as no surprise that, even in their time off, the staff at GCHQ love a good puzzle. Whether they’re recruiting new staff or challenging each other to the toughest Christmas quizzes and treasure hunts imaginable, puzzles are at the heart of what GCHQ does. Now they’re opening up their archives of decades’ worth of codes, puzzles and challenges for everyone to try.
(emphasis in original)
Hard to say if successful completion of the GCHQ Puzzle Book or hacking into GCHQ would be the better way to introduce yourself to the GCHQ.
Depends on which department within GCHQ captures your interest. 😉
Be aware that some pedestrian agencies and their personnel view intrusion into government computers to be crime and punishable as such.
More sophisticated agencies/personnel realize that “…in Jersey, anything is legal so long as you don’t get caught” and/or if you have something of sufficient value to trade.
The “rule of law,” and “letter of the law” stuff is for groundlings. Don’t be a groundling.