Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,u...Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,usually provide limited storage space and relatively low download speed for free users.To achieve better performance,ordinary users have to purchase their expensive services.Moreover,these file management systems are based on centralized architecture and bear the privacy leakage risk,because users’personal files are stored and controlled by their servers.To address the above problems,we propose a peer-to-peer(P2P)file management system based on IPFS and Hyperledger Fabric,named as FileWallet,which can serve as a personal wallet for individual users or organizations to store and share their files in a secure manner.In FileWallet,the users form a P2P network and a Fabric network,where P2P network builds the connections and distributed storage network and the Fabric network sustains consistent blockchain ledgers to record file operation related transactions.In our FileWallet,the storage and communication costs are mitigated in the decentralized design,and the file owner can fully control the access permission of the file to preserve the file privacy.The design of the system architecture,main functionalities,and system implementations are presented in this paper.The performance of the system is evaluated through experiments,and the experimental results show its wide applicability and scalability.展开更多
In recent decades,intelligent transportation systems(ITS)have improved drivers’safety and have shared information(such as traffic congestion and accidents)in a very efficient way.However,the privacy of vehicles and t...In recent decades,intelligent transportation systems(ITS)have improved drivers’safety and have shared information(such as traffic congestion and accidents)in a very efficient way.However,the privacy of vehicles and the security of event information is a major concern.The problem of secure sharing of event information without compromising the trusted third party(TTP)and data storage is the main issue in ITS.Blockchain technologies can resolve this problem.A work has been published on blockchain-based protocol for secure sharing of events and authentication of vehicles.This protocol addresses the issue of the safe storing of event information.However,authentication of vehicles solely depends on the cloud server.As a result,their scheme utilizes the notion of partially decentralized architecture.This paper proposes a novel decentralized architecture for the vehicular ad-hoc network(VANET)without the cloud server.This work also presents a protocol for securing event information and vehicle authentication using the blockchain mechanism.In this protocol,the registered user accesses the event information securely from the interplanetary file system(IPFS).We incorporate the IPFS,along with blockchain,to store the information in a fully distributed manner.The proposed protocol is compared with the state-of-the-art.The comparison provides desirable security at a reasonable cost.The evaluation of the proposed smart contract in terms of cost(GAS)is also discussed.展开更多
Sealed-bid auctions are a vital transaction tool in the e-commerce field.Traditional centralized auction schemes typically result in severe threats to data integrity,information transparency,and traceability owing to ...Sealed-bid auctions are a vital transaction tool in the e-commerce field.Traditional centralized auction schemes typically result in severe threats to data integrity,information transparency,and traceability owing to their excessive reliance on third parties,and blockchain-based auction schemes generally suffer from high storage costs and are deficient in functional and architectural design.To solve these problems,this study presents a sealed-bid auction scheme that removes the third-party based on an Ethereum smart contract,ensuring data integrity,openness,and transparency in the execution process.The commitment mechanism and distributed storage system help to significantly reduce the user’s storage cost and protect the privacy of user bids.For the functional design,this study introduces a fulltext-retrieval and dispute-processing module for commodities,which reduces the defects existing in the functional module design of existing auction systems.Furthermore,a prototype auction system on the Ethereum test chain is built to validate the proposed scheme.Experiments show that compared with traditional storage methods,indirect storage based on a distributed storage system of texts and images can reduce the storage cost by at least 50%while ensuring data integrity.Finally,the gas cost at each stage of the auction scheme and the time required for the full-text retrieval of products are recorded to evaluate the scheme performance and analyze the test results.展开更多
为解决数据混合存储导致精准查找速度慢、数据未分类分级管理造成安全治理难等问题,构建基于主从多链的数据分类分级访问控制模型,实现数据的分类分级保障与动态安全访问。首先,构建链上链下混合式可信存储模型,以平衡区块链面临的存储...为解决数据混合存储导致精准查找速度慢、数据未分类分级管理造成安全治理难等问题,构建基于主从多链的数据分类分级访问控制模型,实现数据的分类分级保障与动态安全访问。首先,构建链上链下混合式可信存储模型,以平衡区块链面临的存储瓶颈问题;其次,提出主从多链架构,并设计智能合约,将不同隐私程度的数据自动存储于从链;最后,以基于角色的访问控制为基础,构建基于主从多链与策略分级的访问控制(MCLP-RBAC)机制并给出具体访问控制流程设计。在分级访问控制策略下,所提模型的吞吐量稳定在360 TPS(Transactions Per Second)左右。与BC-BLPM方案相比,发送速率与吞吐量之比达到1∶1,具有一定优越性;与无访问策略相比,内存消耗降低35.29%;与传统单链结构相比,内存消耗平均降低52.03%;与数据全部上链的方案相比,平均存储空间缩小36.32%。实验结果表明,所提模型能有效降低存储负担,实现分级安全访问,具有高扩展性,适用于多分类数据的管理。展开更多
基金Key-Area Research and Development Program of Guangdong Province No.2020B0101090005National Natural Science Foundation of China under Grant No.62032013,and No.U20B2046+1 种基金111 Project(B16009)the Fundamental Research Funds for the Central Universities N182410001.
文摘Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,usually provide limited storage space and relatively low download speed for free users.To achieve better performance,ordinary users have to purchase their expensive services.Moreover,these file management systems are based on centralized architecture and bear the privacy leakage risk,because users’personal files are stored and controlled by their servers.To address the above problems,we propose a peer-to-peer(P2P)file management system based on IPFS and Hyperledger Fabric,named as FileWallet,which can serve as a personal wallet for individual users or organizations to store and share their files in a secure manner.In FileWallet,the users form a P2P network and a Fabric network,where P2P network builds the connections and distributed storage network and the Fabric network sustains consistent blockchain ledgers to record file operation related transactions.In our FileWallet,the storage and communication costs are mitigated in the decentralized design,and the file owner can fully control the access permission of the file to preserve the file privacy.The design of the system architecture,main functionalities,and system implementations are presented in this paper.The performance of the system is evaluated through experiments,and the experimental results show its wide applicability and scalability.
文摘In recent decades,intelligent transportation systems(ITS)have improved drivers’safety and have shared information(such as traffic congestion and accidents)in a very efficient way.However,the privacy of vehicles and the security of event information is a major concern.The problem of secure sharing of event information without compromising the trusted third party(TTP)and data storage is the main issue in ITS.Blockchain technologies can resolve this problem.A work has been published on blockchain-based protocol for secure sharing of events and authentication of vehicles.This protocol addresses the issue of the safe storing of event information.However,authentication of vehicles solely depends on the cloud server.As a result,their scheme utilizes the notion of partially decentralized architecture.This paper proposes a novel decentralized architecture for the vehicular ad-hoc network(VANET)without the cloud server.This work also presents a protocol for securing event information and vehicle authentication using the blockchain mechanism.In this protocol,the registered user accesses the event information securely from the interplanetary file system(IPFS).We incorporate the IPFS,along with blockchain,to store the information in a fully distributed manner.The proposed protocol is compared with the state-of-the-art.The comparison provides desirable security at a reasonable cost.The evaluation of the proposed smart contract in terms of cost(GAS)is also discussed.
基金National Natural Science Foundation of China(62173066)Open Project of Sichuan Provincial Key Laboratory of Intelligent Terminal Co-built by Province and City(SCITLAB-1014)。
文摘Sealed-bid auctions are a vital transaction tool in the e-commerce field.Traditional centralized auction schemes typically result in severe threats to data integrity,information transparency,and traceability owing to their excessive reliance on third parties,and blockchain-based auction schemes generally suffer from high storage costs and are deficient in functional and architectural design.To solve these problems,this study presents a sealed-bid auction scheme that removes the third-party based on an Ethereum smart contract,ensuring data integrity,openness,and transparency in the execution process.The commitment mechanism and distributed storage system help to significantly reduce the user’s storage cost and protect the privacy of user bids.For the functional design,this study introduces a fulltext-retrieval and dispute-processing module for commodities,which reduces the defects existing in the functional module design of existing auction systems.Furthermore,a prototype auction system on the Ethereum test chain is built to validate the proposed scheme.Experiments show that compared with traditional storage methods,indirect storage based on a distributed storage system of texts and images can reduce the storage cost by at least 50%while ensuring data integrity.Finally,the gas cost at each stage of the auction scheme and the time required for the full-text retrieval of products are recorded to evaluate the scheme performance and analyze the test results.
文摘为解决数据混合存储导致精准查找速度慢、数据未分类分级管理造成安全治理难等问题,构建基于主从多链的数据分类分级访问控制模型,实现数据的分类分级保障与动态安全访问。首先,构建链上链下混合式可信存储模型,以平衡区块链面临的存储瓶颈问题;其次,提出主从多链架构,并设计智能合约,将不同隐私程度的数据自动存储于从链;最后,以基于角色的访问控制为基础,构建基于主从多链与策略分级的访问控制(MCLP-RBAC)机制并给出具体访问控制流程设计。在分级访问控制策略下,所提模型的吞吐量稳定在360 TPS(Transactions Per Second)左右。与BC-BLPM方案相比,发送速率与吞吐量之比达到1∶1,具有一定优越性;与无访问策略相比,内存消耗降低35.29%;与传统单链结构相比,内存消耗平均降低52.03%;与数据全部上链的方案相比,平均存储空间缩小36.32%。实验结果表明,所提模型能有效降低存储负担,实现分级安全访问,具有高扩展性,适用于多分类数据的管理。
