Date Added: Dec 2011
The problem of distributing the key of a symmetric cipher is known as the key distribution problem. The encryption key should be changed as frequently as possible to make it harder for an intruder to break the cipher. In this paper, the proposed quantum key distribution scheme can detect an intruder with a high probability if he eavesdrops while exchanging the secret key. Using standard quantum gates, a quantum circuit is used to create entangled particles from particles in pure states.