Get cracking: work as a team to solve our festive puzzle, says GCHQ

The signals intelligence agency has sent out a challenge aimed at secondary school children on its Christmas cardGCHQ has released seven “fiendish puzzles” for Christmas aimed at secondary school children keen on science, technology and engineering, which it hopes will stimulate interest in its intelligence work and similar careers.The normally secretive signals intelligence agency said completing the seven puzzles, sent out on its Christmas card, would require secondary school class