bdk_message_signer

Note: This is an experimental crate exploring a descriptor-based implementation of BIP-322 within the Bitcoin Dev Kit (BDK) ecosystem.

A Rust library implementing the BIP‑322: Generic Signed Message Format for Bitcoin, built on top of the Bitcoin Dev Kit (BDK) ecosystem.

bdk_message_signer enables cryptographic proof of control over Bitcoin addresses and funds without moving coins or broadcasting transactions, while securely committing to arbitrary messages.

Overview

BIP-322 defines a standardized, script-agnostic mechanism for signing and verifying messages with Bitcoin addresses. Unlike legacy signmessage, BIP-322 works across modern script types (SegWit, Taproot) and enables advanced use cases such as proof-of-funds.

This library provides a descriptor-based, wallet-native implementation of BIP-322, designed for seamless integration with bdk_wallet.

Common use cases

• Proving ownership of Bitcoin addresses
• Cryptographic proof of reserves or funds
• User authentication in Bitcoin-based applications
• Verifying control of addresses for support or dispute resolution
• Hardware-wallet compatible message signing via PSBTs

Integration

Designed to integrate with the Bitcoin Dev Kit ecosystem:

• bdk‑wallet — descriptor-based wallets, key management, and persistence.
• PSBT-based workflows — compatible with hardware and air-gapped signers

No private keys or WIFs are passed directly to this library.

Minimum Supported Rust Version (MSRV)

This crate supports Rust 1.85.0 or newer across all feature combinations.

Supported Signature Formats

• Legacy: Original P2PKH signmessage/verifymessage compatibility
• Simple: SegWit‑only witness stack format
• Full: Complete PSBT/transaction‑based format (any script, including Taproot)
• FullProofOfFunds: Extends Full format with additional UTXO inputs to prove fund ownership.

Usage

Signing a Message

use bdk_wallet::{Wallet, KeychainKind};
use bdk_message_signer::{MessageSigner, SignatureFormat};

// `wallet` is already created and synced
let address = wallet.peek_address(KeychainKind::External, 0).address;

let proof = wallet.sign_message(
    "Hello Bitcoin",
    SignatureFormat::Simple,
    &address,
    None,
)?;

Verifying a Signature

let result = wallet.verify_message(
    &proof,
    "Hello Bitcoin",
    &address,
)?;

assert!(result.valid);

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contributing

Found a bug or have a feature request? Open an issue.