GCHQ CanYouCrackIt Solution explained step by step with videos

 The British spy agency GCHQ recently published a puzzle on www.canyoucrackit.co.uk, just a few days later Dr Gareth Owen, an academic at the University of Greenwich in England has posted a full video explanation of the puzzle. The puzzle has three stages and is not at all simple — likely to challenge even the best computer science graduates.


The first stage is to convert the code on the screen to computer code, which turns out to be a decryption algorithm. The data to be decrypted is hidden in the image on the web site (the image of the numbers).


The second stage asks you to build a virtual computer to run a series of codes - which when run produce the link to the third stage.


The third stage gives you a program to run which requires a licence key - the problem is finding the licence key which requires decoding the program and seeing how it works. Then you have to find three hidden numbers from the first two stages and plug them in to get the web address for the final answer.

Source: http://gchqchallenge.blogspot.com/