Over 600,000 people had a g0 at the quiz but no one got all the answers right, GCHQ said.
However, the government listening agency is giving prizes to three individual members of the public who "came the closest."
The BBC reports that the winners were David MacBryan, 41, from Edinburgh, US-born Kelley Kirklin, 54, from London, and Wim Hulpia, 40, from Lovendegem in Belgium.
They will receive a GCHQ paperweight and a copy of Bletchley Park codebreaker Alan Turing's biography, as well as a personal message from Hannigan and "major bragging rights."
MacBryan told the BBC that he would describe himself as a professional quizmaster. "The more puzzles you do, the better you get at doing puzzles - and I have done a lot of puzzles. I am a bit of an addict," said MacBryan.
More than 30,000 others made it to the final stage.
GCHQ said the puzzle required a mix of mathematical, linguistic, and problem-solving skills.
The first stage of the quiz involved a QR code that led them to questions that were designed to test their analytical prowess and knowledge of phonetics, semaphore, French, snooker, The Lord of the Rings, and more.
The answers are available in full here.