Most synchrotron light storage rings are equipped with a higher harmonic cavity(HHC)and are currently predominantly used to increase beam life.With the enhancement of the beam current intensity,it is necessary to cons...Most synchrotron light storage rings are equipped with a higher harmonic cavity(HHC)and are currently predominantly used to increase beam life.With the enhancement of the beam current intensity,it is necessary to consider instability problems that may be caused by heavy beam loading effects.In this study,we incorporated a HHC into the small-signal Pedersen mathematical model and used system signal analysis to investigate the mode-zero Robinson instability driven by the passive superconducting harmonic cavity and active superconducting harmonic cavity fundamental modes.To further study and alleviate this instability,we introduced direct radio-frequency feedback,an automatic voltage control loop,and a phase-lock loop into the model,discussed the impact of the feedback loop parameter settings on the stability margin,and provided suggestions for parameter settings.展开更多
With the development of cloud computing technology, data can be outsourced to the cloud and conveniently shared among users. However, in many circumstances, users may have concerns about the reliability and integrity ...With the development of cloud computing technology, data can be outsourced to the cloud and conveniently shared among users. However, in many circumstances, users may have concerns about the reliability and integrity of their data. It is crucial to provide data sharing services that satisfy these security requirements. We introduce a reliable and secure data sharing scheme, using the threshold secret sharing technique and the ChaumPedersen zero-knowledge proof. The proposed scheme is not only effective and flexible, but also able to achieve the semantic security property. Moreover, our scheme is capable of ensuring accountability of users’ decryption keys as well as cheater identification if some users behave dishonestly. The efficiency analysis shows that the proposed scheme has a better performance in terms of computational cost, compared with the related work. It is particularly suitable for application to protect users’ medical insurance data over the cloud.展开更多
近年来,如何合理有效地在区块链上实现用户隐私数据保护是区块链技术领域的一个关键性问题.针对此问题,设计出一种基于Pedersen承诺与Schnorr协议的安全多方计算协议(protocol of blockchain based on Pedersen commitment linked Schno...近年来,如何合理有效地在区块链上实现用户隐私数据保护是区块链技术领域的一个关键性问题.针对此问题,设计出一种基于Pedersen承诺与Schnorr协议的安全多方计算协议(protocol of blockchain based on Pedersen commitment linked Schnorr protocol for multi-party computation,BPLSM).通过构筑该协议架构并进行形式化证明演算,表明了该协议能够融入区块链网络、能够在匿名情况下合并不同隐私消息并进行高效签署的特点.此外分析了协议的性质与安全性,证明了在区块链中应用BPLSM协议的泛用型隐私计算方案计算上的低算力开销,并具备良好的信息隐蔽性.最后对协议进行实验仿真,结果表明:在小范围人数固定的多方计算中,BPLSM协议验签的时间成本比当前主流的BLS签名节省约83.5%.展开更多
传统的委托计算需要额外开销验证计算结果的正确性,导致委托计算效率较低、开销较大.针对此问题,结合博弈论与理性信任建模(rational trust modeling,简称RTM)的思想,提出了基于理性信任模型的理性委托计算协议.通过设置恰当的效用函数...传统的委托计算需要额外开销验证计算结果的正确性,导致委托计算效率较低、开销较大.针对此问题,结合博弈论与理性信任建模(rational trust modeling,简称RTM)的思想,提出了基于理性信任模型的理性委托计算协议.通过设置恰当的效用函数,激励计算方诚实执行协议,以此来保证计算结果的可靠性.首先,基于理性信任建模的思想构造理性信任模型,将服务器的生存周期作为效用函数的参数,设计满足委托计算参与者利益的效用函数,并分析协议中参与者的行为策略,当参与者采取"诚实"策略时,可以得到理性委托计算的纳什均衡点;其次,利用改进的NTRU(number theory research unit)公钥密码体制实现速度快、安全性高、具有抵抗量子计算攻击的能力的优点,结合Pedersen承诺方案,设计理性委托计算协议;最后,从正确性、安全性与性能这3个方面对协议进行分析,并通过实验证明生存周期对参与者效用的影响.结果表明,该协议可有效保证计算结果的可靠性.展开更多
文摘Most synchrotron light storage rings are equipped with a higher harmonic cavity(HHC)and are currently predominantly used to increase beam life.With the enhancement of the beam current intensity,it is necessary to consider instability problems that may be caused by heavy beam loading effects.In this study,we incorporated a HHC into the small-signal Pedersen mathematical model and used system signal analysis to investigate the mode-zero Robinson instability driven by the passive superconducting harmonic cavity and active superconducting harmonic cavity fundamental modes.To further study and alleviate this instability,we introduced direct radio-frequency feedback,an automatic voltage control loop,and a phase-lock loop into the model,discussed the impact of the feedback loop parameter settings on the stability margin,and provided suggestions for parameter settings.
基金the National Key R&D Program of China (No. 2017YFB0802000)the National Natural Science Foundation of China (Nos. 61772326 and 61572303)+4 种基金the Research Fund for International Young Scientists, China (No. 61750110528)National Cryptography Development FYind for the 13th Five- Year Plan, China (No. MMJJ20170216), the Foundation of State Key Laboratory of Information Security, China (No. 2017-MS- 03)the Fundamental Research Funds for the Central Universities, China (No. GK201702004)the Scientific Research Program Funded by Shaanxi Provincial Education Department, China (No. 16JK1109), the Provincial Natural Science Foundation Research Project of Shaanxi, China (No. 2017JQ6029)the Doctoral Scientific Fund Project of Shaanxi University of Science & Technology, China (No. BJ11-12).
文摘With the development of cloud computing technology, data can be outsourced to the cloud and conveniently shared among users. However, in many circumstances, users may have concerns about the reliability and integrity of their data. It is crucial to provide data sharing services that satisfy these security requirements. We introduce a reliable and secure data sharing scheme, using the threshold secret sharing technique and the ChaumPedersen zero-knowledge proof. The proposed scheme is not only effective and flexible, but also able to achieve the semantic security property. Moreover, our scheme is capable of ensuring accountability of users’ decryption keys as well as cheater identification if some users behave dishonestly. The efficiency analysis shows that the proposed scheme has a better performance in terms of computational cost, compared with the related work. It is particularly suitable for application to protect users’ medical insurance data over the cloud.
文摘近年来,如何合理有效地在区块链上实现用户隐私数据保护是区块链技术领域的一个关键性问题.针对此问题,设计出一种基于Pedersen承诺与Schnorr协议的安全多方计算协议(protocol of blockchain based on Pedersen commitment linked Schnorr protocol for multi-party computation,BPLSM).通过构筑该协议架构并进行形式化证明演算,表明了该协议能够融入区块链网络、能够在匿名情况下合并不同隐私消息并进行高效签署的特点.此外分析了协议的性质与安全性,证明了在区块链中应用BPLSM协议的泛用型隐私计算方案计算上的低算力开销,并具备良好的信息隐蔽性.最后对协议进行实验仿真,结果表明:在小范围人数固定的多方计算中,BPLSM协议验签的时间成本比当前主流的BLS签名节省约83.5%.
文摘传统的委托计算需要额外开销验证计算结果的正确性,导致委托计算效率较低、开销较大.针对此问题,结合博弈论与理性信任建模(rational trust modeling,简称RTM)的思想,提出了基于理性信任模型的理性委托计算协议.通过设置恰当的效用函数,激励计算方诚实执行协议,以此来保证计算结果的可靠性.首先,基于理性信任建模的思想构造理性信任模型,将服务器的生存周期作为效用函数的参数,设计满足委托计算参与者利益的效用函数,并分析协议中参与者的行为策略,当参与者采取"诚实"策略时,可以得到理性委托计算的纳什均衡点;其次,利用改进的NTRU(number theory research unit)公钥密码体制实现速度快、安全性高、具有抵抗量子计算攻击的能力的优点,结合Pedersen承诺方案,设计理性委托计算协议;最后,从正确性、安全性与性能这3个方面对协议进行分析,并通过实验证明生存周期对参与者效用的影响.结果表明,该协议可有效保证计算结果的可靠性.
