From Symboleo to Smart Contracts : A Code Generator

Abstract

Smart contracts are software systems that monitor and control the execution of legal contracts to ensure compliance with the contracts' terms and conditions. They often exploit Internet-of-Things technologies to support their monitoring functions, and blockchain technology to ensure the integrity of their data. Ethereum and business blockchain platforms, such as Hyperledger Fabric, are among the most popular choices for smart contract development. However, there is a substantial gap in the knowledge of smart contracts between developers and legal experts. Symboleo is a formal specification language for legal contracts that was introduced to address this issue. Symboleo specifications directly encode legal concepts such as parties, obligations, and powers. This thesis proposes a tool-supported method for translating Symboleo specifications into smart contracts. Its contributions include extensions to the existing Symboleo IDE, the implementation of the ontology and semantics of Symboleo into a reusable library, and the Symboleo2SC tool that generates Hyperledger Fabric code exploiting this library. Symboleo2SC was evaluated with three sample contracts. Experimentation with Symboleo2SC shows that legal contract specifications in Symboleo can be fully converted to smart contracts for monitoring purposes. Moreover, Symboleo2SC helps simplify the smart contract development process, saves development effort, and helps reduce risks of coding errors.