Alice and Bob’s quest through the fascinating quantum mechanics world as a way to avoid archvilainess Eve eavesdropping. In 1994, Peter Shor showed that many of the cryptosystems used today can be broken using a quantum computer. This idea will be explained together with a short overview of qubit systems. Next, we will see how quantum computing gives rise to the possibility of quantum key distribution with unparalleled security. We will end with a brief discussion on post-quantum cryptography concepts.