iSyn: Semi-automated Smart Contract Synthesis from Legal Financial Agreements

Abstract

Embracing software-driven smart contracts to fulfill legal agreements is a promising direction for digital transformation in the legal sector. Existing solutions mostly consider smart contracts as simple add-ons, without leveraging the programmability of smart contracts to realize complex semantics of legal agreements. In this paper, we propose iSyn, the first end-to-end system that synthesizes smart contracts to fulfill the semantics of financial legal agreements, with minimal human interventions. The design of iSyn centers around a novel intermediate representation (SmartIR) that closes the gap between the natural language sentences and smart contract statements. Specifically, iSyn includes a synergistic pipeline that unifies multiple NLP-techniques to accurately construct SmartIR instances given legal agreements, and performs template-based synthesis based on the SmartIR instances to synthesize smart contracts. We also design a validation framework to verify the correctness and detect known vulnerabilities of the synthesized smart contracts.We evaluate iSyn using legal agreements centering around financial transactions. The results show that iSyn-synthesized smart contracts are syntactically similar and semantically correct (or within a few edits), compared with the "ground truth"smart contracts manually developed by inspecting the legal agreements.