Trusting Computing as a Service for Blockchain Applications

Recently, blockchain and smart contracts have been one of most popular technology to establish trustworthy applications in several fields. However, due to the transparency and publicity of blockchain, the information processed by a smart contract is visible to every party in a blockchain. In light of this, this study proposes a trusted computing as a service (TCaaS) framework based on the blockchain. One of the critical component is the Execution Environment for Secured Smart Contract Computing (ESC)2 node. In the proposed framework, people can deploy (ESC)2 nodes in a blockchain. Users can upload general-purposed programs and associated parameters and discover an (ESC)2 node for execution via related smart contracts. The programs and parameters are encrypted so that only selected (ESC)2 node can decrypt the data. Then the execution environment calculates the result and returns it to the blockchain. We evaluate our concept with the ESP32 microcontroller with the ATECC508A security chip and the Quorum blockchain platform. Therefore, the study contributes to ensure faithful execution of programs without losing confidentiality.