CATANA: Replay Testing for the Ethereum Blockchain

Blockchain technology is increasingly being adopted in various domains where the immutability of recorded information can foster trust among stakeholders. However, upgradeability mechanisms such as the proxy pattern permit modifying the terms encoded by a Smart Contract even after its deployment. Ensuring that such changes do not impact previous users is of paramount importance. This paper introduces CATANA, a replay testing approach for proxy-based Ethereum applications. Experiments conducted on real-world projects demonstrate the viability of using the public history of transactions to evaluate new versions of a deployed contract and perform more reliable upgrades.