hwi

HWI, in the context of cryptocurrency, stands for Hardware Wallet Interface. It refers to a software layer and toolset designed to enable standardized communication between host software and hardware wallets. The goal is to keep private keys securely on the hardware device while allowing the host to request operations such as deriving addresses, signing transactions, and deriving public keys.

Overview: The Hardware Wallet Interface project provides a command-line interface and library that supports multiple hardware wallet models. It enables workflows for offline signing and is commonly used to integrate hardware wallets with wallet software and Bitcoin Core PSBT workflows.

Functionality: Typical features include enumerating connected devices, requesting public keys and addresses, signing Partially Signed Bitcoin Transactions (PSBTs) or fully signed transactions, and handling derivation paths per BIP-32. The interface translates host requests into device-specific commands and returns results.

Devices and compatibility: HWI supports devices from major vendors such as Ledger, Trezor, and KeepKey; support for other models may vary by version. The project emphasizes vendor-agnostic workflows to facilitate multisig and air-gapped setups.

Impact and usage: By enabling secure offline signing, HWI has become a common component in Bitcoin ecosystems, used by developers and users who prefer hardware wallets for key storage. It is often employed alongside wallets that support PSBT workflows, as well as in offline signing and testing environments.

Development and availability: The project is open-source and hosted on public repositories, with ongoing community maintenance and contributions. It is used by various software projects to provide hardware wallet support.

See also: Hardware wallet, PSBT, Bitcoin Core, Multisignature. Note: HWI can also refer to other, non-cryptocurrency terms in different contexts.