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
Studies have demonstrated that advanced technology,such as smart contract applications,can enhance both pre-and post-contract administration within the built environment sector.Smart contract technology,exemplifying b...Studies have demonstrated that advanced technology,such as smart contract applications,can enhance both pre-and post-contract administration within the built environment sector.Smart contract technology,exemplifying blockchain technologies,has the potential to improve transparency,trust,and the security of data transactions within this sector.However,there is a dearth of academic literature concerning smart contract applications within the construction industries of developing countries,with a specific focus on Nigeria.Consequently,this study seeks to explore the relevance of smart contract technology and address the challenges impeding its adoption,offering strategies to mitigate the obstacles faced by smart contract applications.To investigate the stakeholders,this research conducted 14 virtual interview sessions to achieve data saturation.The interviewees encompassed project management practitioners,senior management personnel from construction companies,experts in construction dispute resolution,professionals in construction software,and representatives from government construction agencies.The data obtained from these interviews underwent thorough analysis employing a thematic approach.The study duly recognizes the significance of smart contract applications within the sector.Among the 12 identified barriers,issues such as identity theft and data leakage,communication and synchronization challenges,high computational expenses,lack of driving impetus,excessive electricity consumption,intricate implementation processes,absence of a universally applicable legal framework,and the lack of a localized legal framework were recurrent impediments affecting the adoption of smart contract applications within the sector.The study also delves into comprehensive measures to mitigate these barriers.In conclusion,this study critically evaluates the relevance of smart contract applications within the built environment,with a specific focus on promoting their usage.It may serve as a pioneering effort,especially within the con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.
基金funded by Faculty of Engineering and the Built Environment and Construction Industry Development Board(CIDB)Centre of Excellence,University of Johannesburg,South Africa(Grant No.05-35-061890).
文摘Studies have demonstrated that advanced technology,such as smart contract applications,can enhance both pre-and post-contract administration within the built environment sector.Smart contract technology,exemplifying blockchain technologies,has the potential to improve transparency,trust,and the security of data transactions within this sector.However,there is a dearth of academic literature concerning smart contract applications within the construction industries of developing countries,with a specific focus on Nigeria.Consequently,this study seeks to explore the relevance of smart contract technology and address the challenges impeding its adoption,offering strategies to mitigate the obstacles faced by smart contract applications.To investigate the stakeholders,this research conducted 14 virtual interview sessions to achieve data saturation.The interviewees encompassed project management practitioners,senior management personnel from construction companies,experts in construction dispute resolution,professionals in construction software,and representatives from government construction agencies.The data obtained from these interviews underwent thorough analysis employing a thematic approach.The study duly recognizes the significance of smart contract applications within the sector.Among the 12 identified barriers,issues such as identity theft and data leakage,communication and synchronization challenges,high computational expenses,lack of driving impetus,excessive electricity consumption,intricate implementation processes,absence of a universally applicable legal framework,and the lack of a localized legal framework were recurrent impediments affecting the adoption of smart contract applications within the sector.The study also delves into comprehensive measures to mitigate these barriers.In conclusion,this study critically evaluates the relevance of smart contract applications within the built environment,with a specific focus on promoting their usage.It may serve as a pioneering effort,especially within the con
