Puzzles were first included in 2015 and have become an annual tradition. The card can be downloaded from the GCHQ website, and has become popular with teachers – the agency says a third of ...

Puzzles were first included in 2015 and have become an annual tradition. The card can be downloaded from the GCHQ website, and has become popular with teachers — the agency says a third of ...

The card features a map of the U.K., linked to the locations where GCHQ has bases, including its high-tech headquarters in Cheltenham, western England, nicknamed the doughnut because of its shape.