Quantum Cryptography is an approach to securing communications by applying the phenomena of quantum physics. Unlike traditional classical cryptography, which uses mathematical techniques to restrict eavesdroppers, quantum cryptography is focused on the physics of information. Quantum cryptography provides secure communication, whose security depends only on the validity of quantum theory, i.e., it is guarantied directly by the laws of physics. This is a substantial difference from any classical cryptographic techniques. This article summarizes the current state of quantum cryptography and provides potential extensions of its feasibility as a mechanism for securing existing communication systems.