The Internet of Vehicles(IoV)operates in highly dynamic and open network environments and faces serious challenges in secure and real-time authentication and consensus mechanisms.Existing methods often suffer from com...The Internet of Vehicles(IoV)operates in highly dynamic and open network environments and faces serious challenges in secure and real-time authentication and consensus mechanisms.Existing methods often suffer from complex certificate management,inefficient consensus protocols,and poor resilience in high-frequency communication,resulting in high latency,poor scalability,and unstable network performance.To address these issues,this paper proposes a secure and efficient distributed authentication scheme for IoV with reputation-driven consensus and SM9.First,this paper proposes a decentralized authentication architecture that utilizes the certificate-free feature of SM9,enabling lightweight authentication and key negotiation,thereby reducing the complexity of key management.To ensure the traceability and global consistency of authentication data,this scheme also integrates blockchain technology,applying its inherent invariance.Then,this paper introduces a reputation-driven dynamic node grouping mechanism that transparently evaluates and groups’node behavior using smart contracts to enhance network stability.Furthermore,a new RBSFT(Reputation-Based SM9 Friendly-Tolerant)consensus mechanism is proposed for the first time to enhance consensus efficiency by optimizing the PBFT algorithm.RBSFT aims to write authentication information into the blockchain ledger to achieve multi-level optimization of trust management and decision-making efficiency,thereby significantly improving the responsiveness and robustness in high-frequency IoV scenarios.Experimental results show that it excels in authentication,communication efficiency,and computational cost control,making it a feasible solution for achieving IoV security and real-time performance.展开更多
稀土元素钐(Samarium,Sm)及其合金在永磁材料领域应用广泛,但其高昂的提取成本与繁琐的制备工艺严重制约发展,亟需开发新型制备方法。本研究旨在阐明Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO复合氧化物在CaCl_(2)-NaCl熔盐中的电化学行为,为...稀土元素钐(Samarium,Sm)及其合金在永磁材料领域应用广泛,但其高昂的提取成本与繁琐的制备工艺严重制约发展,亟需开发新型制备方法。本研究旨在阐明Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO复合氧化物在CaCl_(2)-NaCl熔盐中的电化学行为,为制备Sm-Zn合金提供理论依据。本文采用熔盐电脱氧法,在CaCl_(2)-NaCl熔盐体系中构建三电极系统,通过循环伏安法(Cyclic Voltammetry,CV)和方波伏安法(Square Wave Voltammetry,SWV)对Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO三种金属氧化物的电化学行为进行研究分析。研究结果表明:Sm_(2)O_(3)还原为金属Sm的还原电位约为-1.80 V vs.Ag/Ag^(+),直接电脱氧效率较低;ZnO转化为金属Zn的还原电位约为-0.75 V vs.Ag/Ag^(+);Sm_(2)O_(3)-ZnO混合物在-1.13 V vs.Ag/Ag^(+)左右被还原为SmZn12,在约-1.56 V vs.Ag/Ag^(+)处被还原形成Sm_(2)Zn_(17)合金。不同电解条件下的产物分析结果显示,相比-1.70 V vs.Ag/Ag^(+),在-2.30 V vs.Ag/Ag^(+)、923 K条件下对Sm_(2)O_(3)-ZnO进行20 h恒电位电解时Sm_(2)O_(3)-ZnO能完全转化为SmZn12和Sm_(2)Zn_(17)合金。本研究为稀土金属氧化物熔盐电解制备稀土金属及其合金提供了重要的电化学机制信息与工艺优化路径选择。展开更多
针对车载自组织网络(Vehicular Ad Hoc Network,VANET)中的隐私保护问题,提出一种基于SM9算法的聚合签名方案。该方案以SM9签名算法为基础,结合聚合签名技术提高认证效率,利用雾计算降低时延,实现对数据的实时处理需求,同时满足条件隐...针对车载自组织网络(Vehicular Ad Hoc Network,VANET)中的隐私保护问题,提出一种基于SM9算法的聚合签名方案。该方案以SM9签名算法为基础,结合聚合签名技术提高认证效率,利用雾计算降低时延,实现对数据的实时处理需求,同时满足条件隐私保护、匿名性和不可链接性等安全需求。最后,通过假名机制保护车辆隐私,确保当车辆发生非法行为时能够快速追踪其真实身份。在随机谕言机模型下,证明了该方案的不可伪造性。性能分析结果表明,与现有方案相比,所提方案有效降低了聚合验证阶段的计算开销,适用于资源受限的车联网环境。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61762071,Grant No.61163025).
文摘The Internet of Vehicles(IoV)operates in highly dynamic and open network environments and faces serious challenges in secure and real-time authentication and consensus mechanisms.Existing methods often suffer from complex certificate management,inefficient consensus protocols,and poor resilience in high-frequency communication,resulting in high latency,poor scalability,and unstable network performance.To address these issues,this paper proposes a secure and efficient distributed authentication scheme for IoV with reputation-driven consensus and SM9.First,this paper proposes a decentralized authentication architecture that utilizes the certificate-free feature of SM9,enabling lightweight authentication and key negotiation,thereby reducing the complexity of key management.To ensure the traceability and global consistency of authentication data,this scheme also integrates blockchain technology,applying its inherent invariance.Then,this paper introduces a reputation-driven dynamic node grouping mechanism that transparently evaluates and groups’node behavior using smart contracts to enhance network stability.Furthermore,a new RBSFT(Reputation-Based SM9 Friendly-Tolerant)consensus mechanism is proposed for the first time to enhance consensus efficiency by optimizing the PBFT algorithm.RBSFT aims to write authentication information into the blockchain ledger to achieve multi-level optimization of trust management and decision-making efficiency,thereby significantly improving the responsiveness and robustness in high-frequency IoV scenarios.Experimental results show that it excels in authentication,communication efficiency,and computational cost control,making it a feasible solution for achieving IoV security and real-time performance.
文摘稀土元素钐(Samarium,Sm)及其合金在永磁材料领域应用广泛,但其高昂的提取成本与繁琐的制备工艺严重制约发展,亟需开发新型制备方法。本研究旨在阐明Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO复合氧化物在CaCl_(2)-NaCl熔盐中的电化学行为,为制备Sm-Zn合金提供理论依据。本文采用熔盐电脱氧法,在CaCl_(2)-NaCl熔盐体系中构建三电极系统,通过循环伏安法(Cyclic Voltammetry,CV)和方波伏安法(Square Wave Voltammetry,SWV)对Sm_(2)O_(3)、ZnO及Sm_(2)O_(3)-ZnO三种金属氧化物的电化学行为进行研究分析。研究结果表明:Sm_(2)O_(3)还原为金属Sm的还原电位约为-1.80 V vs.Ag/Ag^(+),直接电脱氧效率较低;ZnO转化为金属Zn的还原电位约为-0.75 V vs.Ag/Ag^(+);Sm_(2)O_(3)-ZnO混合物在-1.13 V vs.Ag/Ag^(+)左右被还原为SmZn12,在约-1.56 V vs.Ag/Ag^(+)处被还原形成Sm_(2)Zn_(17)合金。不同电解条件下的产物分析结果显示,相比-1.70 V vs.Ag/Ag^(+),在-2.30 V vs.Ag/Ag^(+)、923 K条件下对Sm_(2)O_(3)-ZnO进行20 h恒电位电解时Sm_(2)O_(3)-ZnO能完全转化为SmZn12和Sm_(2)Zn_(17)合金。本研究为稀土金属氧化物熔盐电解制备稀土金属及其合金提供了重要的电化学机制信息与工艺优化路径选择。
文摘针对车载自组织网络(Vehicular Ad Hoc Network,VANET)中的隐私保护问题,提出一种基于SM9算法的聚合签名方案。该方案以SM9签名算法为基础,结合聚合签名技术提高认证效率,利用雾计算降低时延,实现对数据的实时处理需求,同时满足条件隐私保护、匿名性和不可链接性等安全需求。最后,通过假名机制保护车辆隐私,确保当车辆发生非法行为时能够快速追踪其真实身份。在随机谕言机模型下,证明了该方案的不可伪造性。性能分析结果表明,与现有方案相比,所提方案有效降低了聚合验证阶段的计算开销,适用于资源受限的车联网环境。
