The problem with this book is not so much the technical absurdities, but rather with the strong implication of technical accuracy the author claims in the pages before the book starts.Personal ignorance of computers, encryption, security and normal engineering are all prerequisite for enjoying this book.Again, to all those who think those complaining about technical "inaccuracies" are nit-picking; Brown makes the strong implicit claim that he knows what he's talking about. The selling point of the book is that it's a PLAUSIBLE, well researched work of fiction. It is not plausible, it is not well researched; it is a work of fiction.As such it is a very poor 'techno-thriller' with no qualities to appeal to anyone with even a rudimentary knowledge of what the book is about. IE National security, computer security, code breaking and writing, etc.The only enjoyment I received from this book was in discussing it's many absurdities with my friends.