Quantum cryptography is a technique to distribute a sequence of truly random
and unconditionally secure bits over a secure communication by applying the
phenomena of quantum physics. The distributed secret bits perform the secret key
which is used later to encrypt messages with an encryption algorithm, usually the
One-Time-Pad is used. Quantum Key Distribution solves the security problem in
classical cryptography by depending on the laws of physics which is focusing on
the physics of information. Quantum protocol gain usually is low due to the
quantum channel noise and the difference between the photon polarization at the
sender and receiver side; in this research, a method is proposed to increase the
protocol gain without decreasing the security level of quantum key. BB84 quantum
key distribution algorithm is implemented and simulated with MATLAB R2010a
simulation; and a comparison is made with A. Singh and N. Sharma [14] results.