Hardware Wallet Integration

Hardware wallet integration is the process of connecting web or mobile applications to external cryptographic devices (like Ledger Nano S/X or Trezor) so users can sign blockchain transactions without exposing their private keys. The hardware device stores the key in a secure element and signs transactions internally, communicating only the signature back to the application. Integration requires understanding USB communication protocols (HID on desktop, BLE on mobile), the transaction signing flows for different blockchains, and how to handle device connection/disconnection events gracefully.