a fantastic journey into the world of the smallest particles and its use to implement a tap-proof connection Only the content counts - the substance is irrelevant. (Is teleportation possible?) "There are more things in heaven and earth than are dreamt of in your philosophy, Horatio. (A journey into the unimaginable world of the quantum) The Heisenberg uncertainty principle (Who measures manure even if he measures manure.) Niels Bohr's atomic model (The world as we thought we knew it) And now please turn off your mind! Unbelievable statements about the world of smallest Particle. Does teleportation also transfer information? The phenomenon of Quantum entanglement Flying optical cats (The thought experiment after Erwin Schrödinger) The Double-Slit Experiment Turn One into Two The fantastic properties of the Qbits change of state by Measurement The tunnel effect Einstein was wrong! The wave theory of light Quantum cryptography what is it? The Shor Algorithm entangled states The quantum Fourier transform The BB84 protocol for tap-proof key exchange Polarization and Spin The key exchange with Qbits and why it is practically impossible to eavesdrop Problems with data transmission and possible solutions About quantum computers and their significance for cryptography Myths and reality Are quantum computers always this fast? A look into the future Post-quantum cryptography - where is the journey going?