Trusting Computing as a Service for Blockchain Applications

Blockchain and smart contracts have become one of the most popular technologies to establish decentralized applications. Due to public visibility of data stored in blockchain, the information processed by a smart contract is visible to every party in a blockchain. To improve data confidentiality, this study proposes a trusted computing as a service (TCaaS) framework based on the blockchain. The framework includes a trustworthy node to perform trusted computing. Using the proposed framework, users of blockchain systems can integrate trustworthy node into blockchain systems. Users can also upload general-purposed programs and associated parameters and discover trustworthy node for execution via related smart contracts. The programs and parameters are encrypted so that only selected trustworthy node can decrypt the data. The execution environment returns computed results to the corresponding blockchain system. We evaluate our concept with the ESP32 microcontroller with the ATECC508A security chip and the Quorum blockchain system. Therefore, the study contributes to construct a trusted computing environment for blockchain system and preserve confidentiality at the same time.