Journal of Engineering and Sustainable Development (Mar 2007)
A Comparative Study for New Aspects to Quantum Key Distribution
Abstract
Quantum cryptography is anew branch of physics and cryptography which exploit quantum mechanical phenomena to guarantee the secrecy of cryptographic keys. This paper introduces the basic concepts, problems and methods of quantum key distribution. It introduces some basic knowledge of quantum mechanics and explains how these physical laws can be used in cryptography. The basic protocols of quantum cryptographic used for key distribution based on entangled polarization photons pair are also presented and assessed. The well known concepts based on entangled pairs of photons (Ekert) schemes are presented. In these schemes Alice and Bob perform measurements on each photon along one of two, three or four directions given by unit vectors and (i, j = 1, 2, 3,4) respectively. Therefore the combinations are used from Alice and Bob is four, nine, or sixteen with respect to number of measurement directions (i = 2, 3 or 4) respectively. The analysis and comparative study between these versions are presented
