bdk-sp

Warning

Work in progress. Not recommended for use with bitcoin mainnet.

This is an experimental crate to research the implementation of silent payment tools in BDK.

This is a second iteration of the work initiated in rust-bip352.

Tip

This is a continuation of the changes applied in bdk:feat/silent-payments-with-rust-silentpayments branch, isolated here for better discoverability. The example-crates/justfile has been refactored to work in isolation from the bdk repository.

The project started building on top of rust-silentpayments, but later extracted the needed parts from it and started evolving by its own.

The project follows BIP352 specification, refer to it to learn more about silentpayments. The only dependencies from the library are:

• bitcoin
• serde (optional)

Example

To get started see the encoding::SilentPaymentCode, receive::Scanner or send::XprivSilentPaymentSender structs depending on the silent payment side you want to focus on.

use bdk_sp::{
    bitcoin::{ ... },
    encoding::SilentPaymentCode,
    receive::Scanner,
    send::XprivSilentPaymentSender,
};

// As a RECEIVER
// Create silent payment codes
let secp = Secp256k1::new();
let sp_code = SilentPaymentCode {
    version: 0,
    scan: scan_privkey.public_key(&secp),
    spend: spend_privkey.public_key(&secp),
    network: Network::Regtest,
};

// Get labeled silent payment codes
let label_to_tweak = <HashMap<_, _>>::new();
let label = SilentPaymentCode::get_label(scan_sk, m);
let labelled_sp_code = sp_code.add_label(label)?;
let neg_spend_pk = sp_code.spend.negate(&secp);
let label_pk = labelled_sp_code.spend.combine(&neg_spend_pk)?;
label_to_tweak.insert(label_pk, (label, m));

// Scan for payments to silent payment code
let scanner = Scanner::new(scan_sk, sp_code.spend, label_to_tweak);
let found_spouts = scanner.scan_tx(&tx, &[prevout])?;

// As a SENDER
// Parse silentpayment code strings

let silent_payment_code = SilentPaymentCode::try_from(sp_code.as_str())?;

// Get silent payment code script pub keys
let sp_sender = XprivSilentPaymentSender::new(master_xpriv);

let mut outputs_and_derivation_paths: Vec<(OutPoint, DerivationPath)> = { ... }

let sp_script_pubkeys =
    sp_sender.send_to(&outputs_and_derivation_paths, &[silent_payment_code])?;

let txout = TxOut {
    value: 10000,
    script_pubkey: sp_script_pubkeys
        .first()
        .expect("only provided one silent payment code")
        .clone(),
};

Contributing

Found a bug, have an issue or a feature request? Feel free to open an issue on GitHub. This library is open source licensed under MIT.