Group 1: Wallet Overview - Digital wallets serve as a bridge connecting users to blockchain technology, with a focus on asset security and management [1] - Wallets can be categorized into custodial and non-custodial types, with the former managed by third parties and the latter fully controlled by users [1] - The development cost of wallets is low, but the potential for malicious activities is even lower, highlighting the importance of open-source wallets [1] Group 2: RPC Protocol - The Remote Procedure Call (RPC) protocol is essential for enabling interaction between wallets and blockchains, allowing programs to call subroutines on other computers without additional programming [3] - RPC can be synchronous, requiring the client to wait for a response, or asynchronous, allowing for callback notifications [3] - JSON-RPC has become a mainstream choice due to its stateless and lightweight characteristics, facilitating a focus on business logic rather than protocol details [3] Group 3: Wallet Development Architecture - Reliable wallet construction requires solid underlying blockchain technology support, with developers needing to adapt to various blockchain protocols [3] - For Bitcoin wallets, understanding the UTXO (Unspent Transaction Output) model is crucial for handling transaction creation, signing, and broadcasting [3] - Mobile wallet development frameworks are critical, with iOS favoring Swift or Objective-C and Android preferring Java or Kotlin, while cross-platform frameworks like ReactNative and Flutter enhance code reuse and development efficiency [3] Group 4: Core Functionality - Asset storage and management are central to wallet functionality, necessitating secure storage solutions and encryption algorithms to protect private keys [5] - Transaction functionality must balance convenience and security, ensuring accurate transaction signing and broadcasting, including gas fee calculations for Ethereum transfers [5] - Multi-currency support is becoming a competitive advantage for wallets, requiring developers to understand the technical characteristics of different cryptocurrencies [5] Group 5: Security Practices for Payment Interfaces - Key security elements can be derived from established payment platforms like Alipay, including authorization password verification for sensitive operations and mandatory parameters for transactions [6] - A comprehensive exception handling mechanism is essential for traceability of issues [6] - The development of blockchain wallet interfaces must incorporate these security practices to ensure the wallet acts as a guardian of assets [6]