British media have reported that Williams' Internet history showed an interest in sex games and bondage, but Wilcox said the codebreaker had made only a handful of visits to bondage sites.

CNN: STORY HIGHLIGHTS

To celebrate we've got a stunning postcard from the sun at the exact moment of solstice, some curious Mexican skulls and an amateur codebreaker who thinks he beat British intelligence agencies at their own game.

ENGADGET: Alt-week 12.22.12: strange skulls, solar portraits and 17-minute code cracking

Describing Turing as one of the "great minds of the twentieth century" he said that staff at the organisation had demanded that he make "a big public deal" of Turing's legacy as part of celebrations marking the centenary of the codebreaker's birth.

BBC: Alan Turing's cyber-legacy praised by GCHQ chief