Modeling and Enforcing Access Control Policies for Smart Contracts

Ethereum smart contracts expose their functions to an untrusted network. Therefore, access control is of utmost importance. Nevertheless, many smart contracts have suffered exploits due to improper design or implementation of access control policies. In this work, we propose an approach for modeling role-based access control policies for Ethereum smart contracts on the architecture level, and we describe a process for ensuring that the implementation is correct w.r.t. that model. We achieve this through a combination of code generation, formal verification and static code analysis. Additionally, we provide an argument for the correctness of our approach and demonstrate its feasibility by detecting manually introduced violations in a case study.