Although quantum physics was founded more than ninety years ago this very useful and successful theory still seems unintuitive and puzzling to everyone. Devices relying on quantum effects already found their way into our everyday lives (Lasers, LED lights, Magnetic Resonance Imaging, …), yet they have not changed much our thinking. However, the thoughts of modern physics like R. Feynman, D. Deutsch and Peter Shor may revolutionize the way we think about information and computation. The aim of this talk is to describe basic ideas behind advantages of quantum computers and to explain how they ruin common cryptographic schemes, but gave us unconditionally secure quantum cryptography.