基于非理想量子态制备的实际连续变量量子秘密共享方案  

Practical continuous variable quantum secret sharing scheme based on non-ideal quantum state preparation

作　　者：吴晓东 黄端 Wu Xiao-Dong;Huang Duan(School of Management,Fujian University of Technology,Fuzhou 350118,China;School of Electronic Information,Central South University,Changsha 410083,China)

机构地区：[1]福建理工大学管理学院,福州350118 [2]中南大学电子信息学院,长沙410083

出　　处：《物理学报》2024年第2期93-103,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61972418,61977062,61801522);福建理工大学科研启动基金(批准号:GY-Z22042)资助的课题。

摘　　要：连续变量量子秘密共享方案基于物理学基本定律,能够保证密钥信息的无条件安全.然而,在实际连续变量量子秘密共享方案中,量子态的制备往往并非是理想、完美的,会引入额外的过噪声,影响方案的安全性,因此有必要对其进行分析.本文提出基于非理想量子态制备的实际连续变量量子秘密共享方案.具体而言,在所提出的方案中假定有多个用户,并且任意一个用户的非理想量子态制备,可以描述为相对应的不可信第三方采用相位非敏感放大器,对该用户的理想调制器与激光器进行放大操作.每个用户由于非理想量子态制备所引入的等效过噪声,可以通过相对应的相位非敏感放大器的增益参数进行全面与定量地计算.研究结果表明,连续变量量子秘密共享方案对非理想量子态制备所引入的过噪声非常敏感,因此不可避免地会降低其性能和安全性.幸运的是,本文利用相位非敏感放大器特定的增益公式,获得所提出方案对非理想量子态制备所引入的额外过噪声容忍度的上界限,有效解决由非理想量子态制备所带来的安全隐患.由于考虑了非理想量子态制备所引入的额外过噪声,因此相比于理想连续变量量子秘密共享方案,所提出的方案能够得到更紧的密钥率曲线.这些结果表明,本文所提出的方案能够对连续变量量子秘密共享方案的实际安全性进行改进与完善,为其实用化发展提供理论依据.Continuous variable quantum secret sharing protocol can guarantee the unconditional security of secret key information based on the fundamental laws of physics.However,the state preparation operation may become non-ideal and imperfect in practical continuous variable quantum secret sharing scheme,which will introduce additional excess noise and affect the security of the scheme.Therefore,it is necessary to analyze it.We propose a practical continuous variable quantum secret sharing protocol based on imperfect state preparation.Specifically,in the proposed scheme,we assume that there are multiple users,and the imperfect state preparation performed by any user is equivalent to the corresponding untrusted third party using a phase insensitive amplifier to amplify the ideal modulator and laser owned by the user.The equivalent excess noise introduced by the imperfect state preparation can be calculated comprehensively and quantitatively through the gain of the corresponding phase insensitive amplifier.The results show that the continuous variable quantum secret sharing scheme is sensitive to the excess noise introduced by the imperfect state preparation operation,which will inevitably reduce its performance and security.Fortunately,the upper bound of the additional excess noise tolerance for the imperfect state preparation is achieved by using the specific gain formula of the phase insensitive amplifier,thus the security risks caused by the imperfect state preparation can be effectively solved.Due to considering the additional excess noise introduced by imperfect state preparation,tighter secret key rate curves can be obtained by the proposed scheme than those by the ideal continuous variable quantum secret sharing protocol.These results indicate that the proposed scheme can improve the practical security of continuous variable quantum secret sharing scheme,and provide a theoretical basis for its practical applications.

关 键 词：非理想量子态制备 连续变量 量子秘密共享 

分 类 号：O413[理学—理论物理] TN918.4[理学—物理]