What Is Quantum Cryptography?

Introduction to Quantum Computing

"Quantum cryptography is the science of exploiting quantum mechanical properties to perform cryptographic tasks."  So, cryptography combines and reads a message through a key created by using an algorithm called a password or a cryptosystem.  This enables two parties to communicate with a random common bit sequence which only they know and is used to encrypt or decrypt messages.  Further, quantum cryptography provides the ability to detect the presence of a third party trying to capture the key. 

"Quantum cryptography is a technology that uses quantum physics to secure the distribution of symmetric encryption keys. A more accurate name for it is quantum key distribution (QKD)."