Abstract
The most tangible impact of quantum information processing that we can perceive today is undoubtedly in the area of quantum cryptography. Quantum key distribution protocols, starting with the groundbreaking BB84, are at the heart of actual physical equipment designed to ensure the security of network communications through quantum means. But, despite their practical success, some important questions related to these protocols remain insufficiently explored, even to the point where they give rise to false myths. This chapter dispels these myths showing what is the exact condition necessary to achieve genuine quantum key distribution (and not just key enhancement), how authentication can also be done quantum mechanically and how testing for possible acts of eavesdropping can also be done on qubits that were never "touched" while in transit.