The Improvement of QKD Scheme Based on BB84 Protocol

In order to solve the low key distribution efficiency problem of the BB84 protocol, an improved BB84 quantum key distribution scheme is presented in this paper. Firstly the same polarization basis is used by the sender and the receiver with the consistent agreement. This process could make quantum key distribution rate higher. Then signature combined with the error correction method based on the odd and even parity is used to ensure the safety of the transmission. The analyses results indicate that the advantage of the improved scheme lies in that the all photons sent to Bob by Alice are useful. It can not only reduce the time extracting the original key, but also solve the authentication problem in the process of communication. The key distribution efficiency is two times of the original BB84 protocol improved scheme.