In the area of blockchains, a wallet is anything that manages the access to cryptocurrencies and tokens. Off-chain wallets appear in different forms, from paper wallets to hardware wallets to dedicated wallet apps, while on-chain wallets are realized as smart contracts. Wallet contracts are supposed to increase trust and security by being transparent and by offering features like daily limits, approvals, multiple signatures, and recovery mechanisms. Ethereum is the most prominent platform for both, tokens and smart contracts, and thus also for on-chain wallets. Our work aims at a better understanding of Ethereum on-chain wallets, which represent one of the most frequent types of smart contracts. By analyzing source code, bytecode, and execution traces, we derive usage scenarios and patterns. We discuss several methods for identifying wallet contracts in a semi-automatic manner by looking at the deployed bytecodes and their interaction patterns. We extract blueprints for wallets and thereby compile a ground truth. Furthermore, we differentiate characteristics of wallets in use, and group them into six types. We provide numbers and temporal perspectives regarding the creation and use of wallets. We analyze the data of the Ethereum main chain up to block 8450000, mined on August 30, 2019.

中文翻译：

---

以太坊钱包合约

在区块链领域，钱包是管理对加密货币和代币的访问的任何东西。链下钱包以不同的形式出现，从纸钱包到硬件钱包再到专用钱包应用程序，而链上钱包则以智能合约的形式实现。钱包合约应该通过透明和提供每日限额、批准、多重签名和恢复机制等功能来提高信任度和安全性。以太坊是代币和智能合约最突出的平台，因此也是链上钱包。我们的工作旨在更好地了解以太坊链上钱包，它代表了最常见的智能合约类型之一。通过分析源代码、字节码和执行轨迹，我们得出使用场景和模式。我们通过查看部署的字节码及其交互模式，讨论了几种以半自动方式识别钱包合约的方法。我们提取钱包的蓝图，从而编译出一个基本事实。此外，我们区分使用的钱包的特征，并将它们分为六种类型。我们提供有关创建和使用钱包的数字和时间观点。我们分析了2019年8月30日挖出的以太坊主链到8450000区块的数据。