Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts...Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts where miners can run arbitrary user-defined programs. However, one of the biggest concerns about the blockchain and the smart contract is privacy, since all the transactions on the chain are exposed to the public. In this paper, we present ShadowEth, a system that leverages hardware enclave to ensure the confidentiality of smart contracts while keeping the integrity and availability based on existing public blockchains like Ethereum. ShadowEth establishes a confidential and secure platform protected by trusted execution environment （TEE） off the public blockchain for the execution and storage of private contracts. It only puts the process of verification on the blockchain. We provide a design of our system including a protocol of the cryptographic communication and verification and show the applicability and feasibility of ShadowEth by various case studies. We implement a prototype using the Intel SGX on the Ethereum network and analyze the security and availability of the system.展开更多
INTRODUCTION On October 14,1936,Shipping Tycoon Chen Shuntong(STC),1upon request of the Japanese Daido Kaiun Corporation(Daido Kaiun),and on behalf of his Shanghai Chung Wei Steamship Co.(Shanghai CW),drafted a time c...INTRODUCTION On October 14,1936,Shipping Tycoon Chen Shuntong(STC),1upon request of the Japanese Daido Kaiun Corporation(Daido Kaiun),and on behalf of his Shanghai Chung Wei Steamship Co.(Shanghai CW),drafted a time charter which stipulated a charter period of 13calendar months from the delivery date of November 1 of 1936 to December 1 of 1937 to rent out his 6。展开更多
The 5G mobile Internet facilitates contents generation for online communities and platforms through human-to-human collaboration.Wikipedia,a well-known online community,uses wiki technology to build an encyclopedia th...The 5G mobile Internet facilitates contents generation for online communities and platforms through human-to-human collaboration.Wikipedia,a well-known online community,uses wiki technology to build an encyclopedia through collective intelligence and collaboration.Mainstream wiki systems adopt a centralized implementation,and while existing studies have optimized the efficiency of the wiki systems'centralized implementation,these systems still suffer from a lot of problems,for example,opacity and distrust.Over the years,blockchain has brought a flurry of fervour and decentralization to the system architecture,meanwhile giving users a sense of trust and participation.Thus,an innovative blockchain-enabled wiki framework called DecWiki is proposed to build one transparent,truthful,collaborative and autonomous encyclopedia.After several participatory design iterations,we present DecWiki's detailed architecture and its implementation in the form of a smart contract and use the interplanetary file system to complement the big data storage.Meanwhile,we use the trusted execution environment to secure sensitive information in the wireless scenario.Finally,the system overhead and the acceptance of the prototype are evaluated.Extensive experiments present its significant performance.展开更多
基金This work was supported by the National Key Research and Development Program of China under Grant No. 2016YFB1000104, the National Natural Science Foundation of China under Grant Nos. 61572314 and 61525204, and the Young Scientists Fund of the National Natural Science Foundation of China under Grant No. 61303011.
文摘Blockchain is becoming popular as a distributed and reliable ledger which allows distrustful parties to transact safely without trusting third parties. Emerging blockchain systems like Ethereum support smart contracts where miners can run arbitrary user-defined programs. However, one of the biggest concerns about the blockchain and the smart contract is privacy, since all the transactions on the chain are exposed to the public. In this paper, we present ShadowEth, a system that leverages hardware enclave to ensure the confidentiality of smart contracts while keeping the integrity and availability based on existing public blockchains like Ethereum. ShadowEth establishes a confidential and secure platform protected by trusted execution environment （TEE） off the public blockchain for the execution and storage of private contracts. It only puts the process of verification on the blockchain. We provide a design of our system including a protocol of the cryptographic communication and verification and show the applicability and feasibility of ShadowEth by various case studies. We implement a prototype using the Intel SGX on the Ethereum network and analyze the security and availability of the system.
文摘INTRODUCTION On October 14,1936,Shipping Tycoon Chen Shuntong(STC),1upon request of the Japanese Daido Kaiun Corporation(Daido Kaiun),and on behalf of his Shanghai Chung Wei Steamship Co.(Shanghai CW),drafted a time charter which stipulated a charter period of 13calendar months from the delivery date of November 1 of 1936 to December 1 of 1937 to rent out his 6。
基金supported by the National Natural Science Foundation of China(NSFC)under Grant No.61932007.
文摘The 5G mobile Internet facilitates contents generation for online communities and platforms through human-to-human collaboration.Wikipedia,a well-known online community,uses wiki technology to build an encyclopedia through collective intelligence and collaboration.Mainstream wiki systems adopt a centralized implementation,and while existing studies have optimized the efficiency of the wiki systems'centralized implementation,these systems still suffer from a lot of problems,for example,opacity and distrust.Over the years,blockchain has brought a flurry of fervour and decentralization to the system architecture,meanwhile giving users a sense of trust and participation.Thus,an innovative blockchain-enabled wiki framework called DecWiki is proposed to build one transparent,truthful,collaborative and autonomous encyclopedia.After several participatory design iterations,we present DecWiki's detailed architecture and its implementation in the form of a smart contract and use the interplanetary file system to complement the big data storage.Meanwhile,we use the trusted execution environment to secure sensitive information in the wireless scenario.Finally,the system overhead and the acceptance of the prototype are evaluated.Extensive experiments present its significant performance.
