关键词:
Smart contract
摘要:
With the booming development of blockchain, it has gradually gained wide attention in the Internet of Things, finance, and other fields. However, the ledger of the blockchain is shared, so that any user in the blockchain can directly access sensitive information contained in the smart contract, such as transaction amounts and private agreements, raising serious privacy concerns for their millions of users. To solve this problem, we propose TrustChain, a performant smart contract model to protect both code and data privacy based on Trusted Execution Environment (TEE). Specially, we introduce the TEE to run the smart contract with security and privacy without introducing a heavyweight cryptographic algorithm, thus improving the performance of the system. The operate nodes equipped with TEE directly download the smart contract code from the smart contract maker through key negotiation when the smart contract is invoked, which isolate the sensitive information of the smart contract from the outside world. Furthermore, we introduce the verifiable random functions to distributed randomly choose the operate nodes to prevent collusion attacks, further improving the security of the model. Another contribution of this paper is that the graph ledger based on the directed acyclic graph is used to adapt to the high-performance characteristics of smart contract system based on TEE. Finally, we simulate the scheme in Trustzone and demonstrate the feasibility of TrustChain through a series of experiments and analyses. The analysis and experimental results show that our scheme has a good performance of privacy protection and the throughput of our scheme is 34% higher than that of the traditional smart contract. © 2023, The Authors. All rights reserved.