Remote data auditing becomes critical to ensure the storage reliability in distributed cloud storage.Recently,Le et al proposed an efficient private data auditing scheme NC-Audit designed for regenerating codes,which ...Remote data auditing becomes critical to ensure the storage reliability in distributed cloud storage.Recently,Le et al proposed an efficient private data auditing scheme NC-Audit designed for regenerating codes,which claimed that NC-Audit can effectively realize privacy-preserving data auditing for distributed storage systems.However,our analysis shows that NC-Audit is not secure for that the adversarial cloud can forge some illegal blocks to cheat the auditor successfully with a high probability even without storing the user’s whole data,when the coding field is large enough.展开更多
内部电网地理信息系统(Geographic Information Systern,GIS)数据体量增加,对电网数据存储性能造成了极大的困难,为此,提出一种基于随机森林的电网GIS数据分布式存储方法。以跨域资源共享(Cross-Origin Resource Sharing,CORS)技术在电...内部电网地理信息系统(Geographic Information Systern,GIS)数据体量增加,对电网数据存储性能造成了极大的困难,为此,提出一种基于随机森林的电网GIS数据分布式存储方法。以跨域资源共享(Cross-Origin Resource Sharing,CORS)技术在电网GIS空间信息服务平台中获取的电网GIS数据为基础,根据类区分度数值选择电网GIS数据特征,引入随机森林算法分类处理电网GIS数据,将其合理分发给不同的服务器,采用并行处理手段存储分类数据,从而实现了电网GIS数据的分布式存储。实验数据显示:应用所提方法后,电网GIS数据分类精度达到了96.8%,电网GIS数据分布式存储时间最小值为5.2 s,充分证实了所提方法数据存储性能更佳。展开更多
在当今信息时代,数据的复杂性不断增加,传统的关系型数据库在大规模数据存储和处理方面面临着挑战。非关系型数据库(Not Only SQL,NoSQL)作为一种新的存储和处理数据的方法,受到了广泛关注,并在分布式存储领域取得了显著的成就。文章重...在当今信息时代,数据的复杂性不断增加,传统的关系型数据库在大规模数据存储和处理方面面临着挑战。非关系型数据库(Not Only SQL,NoSQL)作为一种新的存储和处理数据的方法,受到了广泛关注,并在分布式存储领域取得了显著的成就。文章重点探讨基于大数据技术的非关系型数据库分布式存储方法,并通过实验进行评估,发现其在可扩展性和安全性方面具有优势,可以为相关研究提供参考。展开更多
This paper takes the Sobel operator as example to study parallel sequential algorithm onto a memory-sharing multiprocessor by using a virtual machine. Several different parallel algorithms using function decomposition...This paper takes the Sobel operator as example to study parallel sequential algorithm onto a memory-sharing multiprocessor by using a virtual machine. Several different parallel algorithms using function decomposition and/or data decomposition methods are compared and their performances are analyzed in terms of processor utilization, data traffic, shared memory access, and synchronization overhead. The analysis is validated through a simulation experiment on the virtual machine of 64 parallel processors. Conclusions are presented at the end of this paper.展开更多
Vehicular Ad hoc Networks(VANETs)become a very crucial addition in the Intelligent Transportation System(ITS).It is challenging for a VANET system to provide security services and parallelly maintain high throughput b...Vehicular Ad hoc Networks(VANETs)become a very crucial addition in the Intelligent Transportation System(ITS).It is challenging for a VANET system to provide security services and parallelly maintain high throughput by utilizing limited resources.To overcome these challenges,we propose a blockchain-based Secured Cluster-based MAC(SCB-MAC)protocol.The nearby vehicles heading towards the same direction will form a cluster and each of the clusters has its blockchain to store and distribute the safety messages.The message which contains emergency information and requires Strict Delay Requirement(SDR)for transmission are called safety messages(SM).Cluster Members(CMs)sign SMs with their private keys while sending them to the blockchain to confirm authentication,integrity,and confidentiality of the message.A Certificate Authority(CA)is responsible for physical verification,key generation,and privacy preservation of the vehicles.We implemented a test scenario as proof of concept and tested the safety message transmission(SMT)protocol in a real-world platform.Computational and storage overhead analysis shows that the proposed protocol for SMT implements security,authentication,integrity,robustness,non-repudiation,etc.while maintaining the SDR.Messages that are less important compared to the SMs are called non-safety messages(NSM)and vehicles use RTS/CTS mechanism for NSM transmission.Numerical studies show that the proposed NSM transmission method maintains 6 times more throughput,2 times less delay and 125%less Packet Dropping Rate(PDR)than traditional MAC protocols.These results prove that the proposed protocol outperforms the traditional MAC protocols.展开更多
基金Supported by the National Natural Science Foundation of China(61872088)the Science and Technology Plan Project of Xi’an(2020KJWL02,2017CGWL35)the China National Study Abroad Fund。
文摘Remote data auditing becomes critical to ensure the storage reliability in distributed cloud storage.Recently,Le et al proposed an efficient private data auditing scheme NC-Audit designed for regenerating codes,which claimed that NC-Audit can effectively realize privacy-preserving data auditing for distributed storage systems.However,our analysis shows that NC-Audit is not secure for that the adversarial cloud can forge some illegal blocks to cheat the auditor successfully with a high probability even without storing the user’s whole data,when the coding field is large enough.
文摘在当今信息时代,数据的复杂性不断增加,传统的关系型数据库在大规模数据存储和处理方面面临着挑战。非关系型数据库(Not Only SQL,NoSQL)作为一种新的存储和处理数据的方法,受到了广泛关注,并在分布式存储领域取得了显著的成就。文章重点探讨基于大数据技术的非关系型数据库分布式存储方法,并通过实验进行评估,发现其在可扩展性和安全性方面具有优势,可以为相关研究提供参考。
文摘This paper takes the Sobel operator as example to study parallel sequential algorithm onto a memory-sharing multiprocessor by using a virtual machine. Several different parallel algorithms using function decomposition and/or data decomposition methods are compared and their performances are analyzed in terms of processor utilization, data traffic, shared memory access, and synchronization overhead. The analysis is validated through a simulation experiment on the virtual machine of 64 parallel processors. Conclusions are presented at the end of this paper.
文摘Vehicular Ad hoc Networks(VANETs)become a very crucial addition in the Intelligent Transportation System(ITS).It is challenging for a VANET system to provide security services and parallelly maintain high throughput by utilizing limited resources.To overcome these challenges,we propose a blockchain-based Secured Cluster-based MAC(SCB-MAC)protocol.The nearby vehicles heading towards the same direction will form a cluster and each of the clusters has its blockchain to store and distribute the safety messages.The message which contains emergency information and requires Strict Delay Requirement(SDR)for transmission are called safety messages(SM).Cluster Members(CMs)sign SMs with their private keys while sending them to the blockchain to confirm authentication,integrity,and confidentiality of the message.A Certificate Authority(CA)is responsible for physical verification,key generation,and privacy preservation of the vehicles.We implemented a test scenario as proof of concept and tested the safety message transmission(SMT)protocol in a real-world platform.Computational and storage overhead analysis shows that the proposed protocol for SMT implements security,authentication,integrity,robustness,non-repudiation,etc.while maintaining the SDR.Messages that are less important compared to the SMs are called non-safety messages(NSM)and vehicles use RTS/CTS mechanism for NSM transmission.Numerical studies show that the proposed NSM transmission method maintains 6 times more throughput,2 times less delay and 125%less Packet Dropping Rate(PDR)than traditional MAC protocols.These results prove that the proposed protocol outperforms the traditional MAC protocols.
