Chiang Mai Journal of Science

The data encryption/decryption is employed to secure the transported data that is now become very importance issue for communication and networks. however, the general encryption is not absolute secure of the required information. The absolute security techniqueis known as quantum security where the principle of the technique is the technique is that the requred data is encrypted/ decrypted by quantum transported channel. The transported signals are randomly coded/ decoded by using the quantum entanglement pairs. The quantum entangle is created by using a single pulse i.e. single photon that occupies the random polarization states, where the required polarization states can be formed be sender and receiver at any time linking by quantum channel. In this paper, the single pulse is created by a CW laser diode that is launched into the classical Mach-Zehnder Interferometer. The single pulse is generated and detected when a light beam is modulated by signal from signal generator with suitable driven frequency on a LiNbO₃ crystal. Then the entanglement signals can be realized and transmitted via classical optical system. The quantum dense coding can also be performed by the technique of dense wavelength division mutiplexing technique, where each of transmitted wavelengths can be randomly formed entanglement pairs, then the dense conde/ decode schemes casn be employed and linked via cable or wireless transmission.