Every morning, as you swipe your thumb across the screen, something magical happens. Without even realising it, you pass through dozens of security checks that protect your most private messages, your bank accounts and your photos. But the invisible architecture we now take for granted has been built over thousands of years of war, ingenuity and desperation. In this captivating story, IT pioneer Rickard Eriksson takes us on a journey through history – from the Spartan generals’ secret wooden sticks to Alan Turing’s battle against the Nazis’ code-breaking machines and today’s battles between Apple and the FBI. This is not a book about technology. It is a book about truth in a world full of ears. It is the story of how we created a digital world where we dare to trust strangers, and what happens to us when those in power demand to see what we have hidden. Learn to see the invisible world behind the screen – before the next great arms race renders our current locks obsolete.