Research Of Information On The Security Of Quantum Cryptography

As the representative of quantum cryptography, the quantum key distribution (QKD) is a successful model that the quantum information technique is applied in to the conventional communications. The security of the quantum cryptogram is unconditional for the Heisenberg uncertainty principle and quantum state no-cloning theorem, so the quantum cryptogram system has the advantage that tranditional cryptogram system has not.In the Information theory investigation for the quantum cryptography, how we compute the quantity of information that the eavesdropper Eve and legal receiver Bob acquire, and the characteristic of the quantity of information, the boundary of quantity of information, the containing quantity of information in a parity bit etc, are the key problems to quantum cryptography. Only the one know the quantity of information Eve acquiring, then legal correspondent can adopt the valid measurement and guarantee the correspondence safety.In this paper, as the foundation of QKD security research, some quantum physics and information theories are introduced. The principles of the BB84 and B92 protocols are explained at some length. The realization issues of these protocols important for the security aspect are discussed and a review of current experimental progresses in the field is presented. For BB84 and B92 protocols, a detailed investigation is done with the theory about the quantum measurement channel and the quantum information theory. The relation between the mutual information between the signal's deliverer, the legal receiver and the eavesdropper, the bit error rate during propagating the signals and the eavesdropping way are given and some academic criteria for checking Eve is estimated.