量子密钥分配的安全性分析

Analyse on the security of the system for quantum key distribution

量子密钥分配特别适合光通信环境,而且可以实现无条件安全性。但由于现有技术水平的限制,实际量子密钥分配的安全性受到挑战。分析了目前量子密钥分配安全性面临的最大威胁-光子数分离攻击,介绍了两种可以抵制光子数分离攻击的方法:硬件措施-诱惑态方案和软件措施-非中交编码方案,并重点分析了两种方法的原理和特点。

Quantum cryptograph has extraordinary adaptability to the optical communication and unconditional security which classical cryptography has been striving for. Because the technical limition at present, the security of the practical QKD is challenged. The paper analyzes the photon number splitting （PNS） attack which is the biggest threat to the practical QKD, introduces two measures against PNS attack including decoy state method by an easy change of hardware and non-orthogonal encoding protocol by a mere change of software, and analyzes the theories and characters of the two measures.