Secure and Efficient Runtime Environment for Smart Contracts on JointCloud

Many cloud providers, including Amazon, Google, Microsoft, and Alibaba Cloud, offer support for blockchain cloud services that rely on a runtime environment, such as the Ethereum Virtual Machine (EVM), to execute smart contracts and ensure consistency between participants. However, existing runtime systems suffer from two main limitations. Firstly, traditional runtime systems like EVM cannot guarantee privacy protection as all the data uploaded to the blockchain is visible to all participants. This restricts the use of blockchain in limited scenarios. Secondly, each computation on the runtime system must be synchronized to all nodes in the network, resulting in a significant increase in computational overhead, which can be challenging to implement for more complex applications. One approach to address these limitations is to utilize Trusted Execution Environments (TEE) for blockchain runtime, which can provide privacy protection and mitigate redundant synchronization operations. However, using TEE for blockchain may significantly increase cloud costs. To overcome these challenges, this paper proposes PL-EVM, a new runtime environment for smart contracts that utilizes jointcloud. PL-EVM achieves high-security guarantees by using TEE to protect privacy-sensitive data and incorporates dynamic migration and splitting mechanisms to achieve high efficiency and low costs. Our evaluation results show that PL-EVM can improve performance and reduce costs by 4% to 32.22%.