Research On Two-Party Quantum Cryptography Protocol And Its Security

Quantum Key Distribution?QKD?is a technology for sharing keys between two legitimate users,Alice and Bob.It uses quantum effects to provide unconditionally secure message transmission.Ever since the first protocol of quantum communication,i.e.,BB84 protocol,was proposed by Bennett and Brassard in 1984,various variant protocols were proposed and many communication systems were demonstrated.In this paper,we introduce different technologies to two-party cryptography protocols,design new protocols to achieve higher security.First,to solve the security problem of two-party quantum cryptography protocols based on limited memory model,we introduce measurement-device-independent and parameter estimation technologies to two-party quantum cryptography,and design a new protocol.We analyze the security of the protocol based on quantum information theory.The analysis results show that even in the case of unlimited storage,our protocol achieves unconditional security under non-entanglement attacks,and improves the security of the proposed protocol under entanglement attacks.Analysis shows that our protocol raises the upper limit of the key code rate of the two-party encryption protocol to?1/4-?-e_r?n + 1-log1/?²,and reduces the probability of the attacker's successful attack by obtaining the key to ?=(1/2+1/(2?2?^1/2))ⁿSecond,to solve the security of quantum bit commitment protocols,we design a new quantum bit commitment protocol based on linear block code.We introduce the architecture and process of the proposed protocol,and analyze its security.The analysis result shows that when Alice takes an attack measure,the channel error rate increases by at least 12.5%,and Bob cannot obtain any information of Alice before the demystification stage.Third,we find that existing quantum secret sharing protocols based on ring topology cannot resist Trojan horse attacks.We give a modified Trojan horse attack strategy.And show that the eavesdropper can obtain any player's information and the dealer's secret message without being detected.Then we design a defense strategy based on quantum memory.The evaluation results show that after using this defense strategy,the attacker's attack significantly increases the bit error rate.Compared with the failure to adopt our defense strategy,the bit error rate is increased by about 5 times,which will expose the attacker's attack.