Characteristics of Wallet Contracts on Ethereum

For the management of cryptocurrencies or cryptographic tokens, many users employ a software wallet that facilitates the interaction with a blockchain in general or with on-chain programs (smart contracts) in particular. While many blockchain wallets execute their core program code off-chain, some wallets implement core functionality on-chain as smart contracts with the intent to increase trust and security by using transparent and verifiable execution.In this work, we investigate smart contracts for wallets with regard to the functionality that makes use of cryptographically secured blockchain technology. We focus on wallet contracts deployed on Ethereum, as it is the most prominent platform for tokens and smart contracts with readily available data. We aim at a better understanding of this frequently deployed group of smart contracts by analyzing characteristics of wallet contracts and grouping them into six types. To this end, we present approaches to identify wallet contracts by analyzing source code, bytecode, and execution traces extracted from transaction data. Moreover, we investigate usage scenarios and patterns. From the derived data, we extract blueprints for wallets and compile a ground truth. We provide numbers and temporal perspectives regarding the creation and use of wallets.