The client server mode conforms to the trend of the development of MIS. Based on a project of the Guangzhou Power Supply Bureau, the research method and optimization strategy of MIS are put forward using the client ...The client server mode conforms to the trend of the development of MIS. Based on a project of the Guangzhou Power Supply Bureau, the research method and optimization strategy of MIS are put forward using the client server computation mode in a power system enterprise. The structure and function are also introduced.展开更多
With the massive diffusion of cloud computing, more and more sensitive data is being centralized into the cloud for sharing, which brings forth new challenges for the security and privacy of outsourced data. To addres...With the massive diffusion of cloud computing, more and more sensitive data is being centralized into the cloud for sharing, which brings forth new challenges for the security and privacy of outsourced data. To address these challenges, the server-aided access control(SAAC) system was proposed. The SAAC system builds upon a variant of conditional proxy re-encryption(CPRE) named threshold conditional proxy re-encryption(TCPRE). In TCPRE, t out of n proxies can re-encrypt ciphertexts(satisfying some specified conditions) for the delegator(while up to t-1 proxies cannot), and the correctness of the re-encrypted ciphertexts can be publicly verified. Both features guarantee the trust and reliability on the proxies deployed in the SAAC system. The security models for TCPRE were formalized, several TCPRE constructions were proposed and that our final scheme was secure against chosen-ciphertext attacks was proved.展开更多
We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some int...We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some integerξ≥1,with workloads specified by the amount of required resources.If one or more servers fail,the affected workloads can be redirected to other servers that host replicas associated with the same item,such that the service is not interrupted by the failure of up toξservers.This requires that any feasible assignment algorithm must reserve some capacity in each server to accommodate the workload redirected from potential failed servers without overloading,and determining the optimal method for reserving capacity becomes a key issue.Unlike existing algorithms that assume that no two servers share replicas of more than one item,we first formulate capacity reservation for a general arbitrary scenario.Due to the combinatorial nature of this problem,finding the optimal solution is difficult.To this end,we propose a Generalized and Simple Calculating Reserved Capacity(GSCRC)algorithm,with a time complexity only related to the number of items packed in the server.In conjunction with GSCRC,we propose a robust replica packing algorithm with capacity optimization(RobustPack),which aims to minimize the number of servers hosting replicas and tolerate multiple server failures.Through theoretical analysis and experimental evaluations,we show that the RobustPack algorithm can achieve better performance.展开更多
文摘The client server mode conforms to the trend of the development of MIS. Based on a project of the Guangzhou Power Supply Bureau, the research method and optimization strategy of MIS are put forward using the client server computation mode in a power system enterprise. The structure and function are also introduced.
基金The National Natural Science Foundation of China(No.61272413,No.61472165)
文摘With the massive diffusion of cloud computing, more and more sensitive data is being centralized into the cloud for sharing, which brings forth new challenges for the security and privacy of outsourced data. To address these challenges, the server-aided access control(SAAC) system was proposed. The SAAC system builds upon a variant of conditional proxy re-encryption(CPRE) named threshold conditional proxy re-encryption(TCPRE). In TCPRE, t out of n proxies can re-encrypt ciphertexts(satisfying some specified conditions) for the delegator(while up to t-1 proxies cannot), and the correctness of the re-encrypted ciphertexts can be publicly verified. Both features guarantee the trust and reliability on the proxies deployed in the SAAC system. The security models for TCPRE were formalized, several TCPRE constructions were proposed and that our final scheme was secure against chosen-ciphertext attacks was proved.
基金supported in part by the National Key R&D Program of China under No.2023YFB2703800the National Science Foundation of China under Grants U22B2027,62172297,62102262,61902276 and 62272311+3 种基金Tianjin Intelligent Manufacturing Special Fund Project under Grants 20211097the China Guangxi Science and Technology Plan Project(Guangxi Science and Technology Base and Talent Special Project)under Grant AD23026096(Application Number 2022AC20001)Henan Provincial Natural Science Foundation of China under Grant 622RC616CCF-Nsfocus Kunpeng Fund Project under Grants CCF-NSFOCUS202207。
文摘We study a novel replication mechanism to ensure service continuity against multiple simultaneous server failures.In this mechanism,each item represents a computing task and is replicated intoξ+1 servers for some integerξ≥1,with workloads specified by the amount of required resources.If one or more servers fail,the affected workloads can be redirected to other servers that host replicas associated with the same item,such that the service is not interrupted by the failure of up toξservers.This requires that any feasible assignment algorithm must reserve some capacity in each server to accommodate the workload redirected from potential failed servers without overloading,and determining the optimal method for reserving capacity becomes a key issue.Unlike existing algorithms that assume that no two servers share replicas of more than one item,we first formulate capacity reservation for a general arbitrary scenario.Due to the combinatorial nature of this problem,finding the optimal solution is difficult.To this end,we propose a Generalized and Simple Calculating Reserved Capacity(GSCRC)algorithm,with a time complexity only related to the number of items packed in the server.In conjunction with GSCRC,we propose a robust replica packing algorithm with capacity optimization(RobustPack),which aims to minimize the number of servers hosting replicas and tolerate multiple server failures.Through theoretical analysis and experimental evaluations,we show that the RobustPack algorithm can achieve better performance.
