Formal Verification of Smart Contract Based on Timed Colored Petri Net

Abstract

The Blockchain 2.0 era integrated with smart contract along with its platforms and applications have experienced explosive growth in recent years. However, many smart contracts deployed in practice are prone to errors and cannot be modified due to the immutability of the blockchain. In light of this, it is vital to ensure the security of correctness of smart contracts before deployment. This paper proposes a formal modeling method based on Timed Colored Petri net (TCPN) to anlyze smart contracts with time constrains. We apply this formalism to a concrete voting contract system. Its functional requirements are formalized by the improved computing timing logic ASK-CTL with ML (Meta Language). Simulation and experiment show that the security and reliability of the voting contract can be effectively guaranteed.