This is something that I really have and must brag about.
If you ever read Dan Brown’s “Digital Fortress” or “Deception Point”, you shall find two codes at the end of the book.
According to Dan Brown’s Website, the so called “Ultimate code” found in Digital Fortress is hard to break. Well, I broke it. Indeed it took me some time to find the key on how to do it, but once I did I was like “Uuhh, was that all?”, nevertheless, I still found it pure genius. You will also find a very similar code at the end of the Deception Point book, which is at the same time a little bit different.
Next mission after X-Mas, uncover the codes on the “Da Vinci Code” cover.