Skip to content

change NUMS key to bip 0341 one #18

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
apoelstra merged 2 commits into from
Nov 11, 2025
Merged

change NUMS key to bip 0341 one #18

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
2415930
simplicity: refactor taprootspendinfo and address generation
apoelstra Oct 26, 2025
1d211d6
simplicity: switch 'unspendable key' to the one specified in BIP 341
apoelstra Oct 26, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 21 additions & 11 deletions src/hal_simplicity.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@

use std::sync::Arc;

use elements::taproot::{TaprootBuilder, TaprootSpendInfo};
use simplicity::bitcoin::secp256k1;
use simplicity::jet::Jet;
use simplicity::{BitIter, CommitNode, DecodeError, ParseError, RedeemNode};
Expand Down Expand Up @@ -91,12 +92,15 @@ impl<J: Jet> Program<J> {
}
}

// Stolen from simplicity-webide
fn unspendable_internal_key() -> secp256k1::XOnlyPublicKey {
/// The unspendable internal key specified in BIP-0341.
///
/// This is a "nothing up my sleeve" (NUMS) point. See the text of BIP-0341
/// for its derivation.
#[rustfmt::skip] // mangles byte vectors
pub fn unspendable_internal_key() -> secp256k1::XOnlyPublicKey {
secp256k1::XOnlyPublicKey::from_slice(&[
0xf5, 0x91, 0x9f, 0xa6, 0x4c, 0xe4, 0x5f, 0x83, 0x06, 0x84, 0x90, 0x72, 0xb2, 0x6c, 0x1b,
0xfd, 0xd2, 0x93, 0x7e, 0x6b, 0x81, 0x77, 0x47, 0x96, 0xff, 0x37, 0x2b, 0xd1, 0xeb, 0x53,
0x62, 0xd2,
0x50, 0x92, 0x9b, 0x74, 0xc1, 0xa0, 0x49, 0x54, 0xb7, 0x8b, 0x4b, 0x60, 0x35, 0xe9, 0x7a, 0x5e,
0x07, 0x8a, 0x5a, 0x0f, 0x28, 0xec, 0x96, 0xd5, 0x47, 0xbf, 0xee, 0x9a, 0xce, 0x80, 0x3a, 0xc0,
])
.expect("key should be valid")
}
Expand All @@ -106,20 +110,26 @@ fn script_ver(cmr: simplicity::Cmr) -> (elements::Script, elements::taproot::Lea
(script, simplicity::leaf_version())
}

fn taproot_spend_info(cmr: simplicity::Cmr) -> elements::taproot::TaprootSpendInfo {
let builder = elements::taproot::TaprootBuilder::new();
/// Given a Simplicity CMR and an internal key, computes the [`TaprootSpendInfo`]
/// for a Taptree with this CMR as its single leaf.
pub fn taproot_spend_info(
internal_key: secp256k1::XOnlyPublicKey,
cmr: simplicity::Cmr,
) -> TaprootSpendInfo {
let builder = TaprootBuilder::new();
let (script, version) = script_ver(cmr);
let builder = builder.add_leaf_with_ver(0, script, version).expect("tap tree should be valid");
builder
.finalize(secp256k1::SECP256K1, unspendable_internal_key())
.expect("tap tree should be valid")
builder.finalize(secp256k1::SECP256K1, internal_key).expect("tap tree should be valid")
}

/// Given a Simplicity CMR, computes an unconfidential Elements address
/// (for the given network) corresponding to a Taptree with an unspendable
/// internal key and this CMR as its single leaf.
pub fn elements_address(
cmr: simplicity::Cmr,
params: &'static elements::AddressParams,
) -> elements::Address {
let info = taproot_spend_info(cmr);
let info = taproot_spend_info(unspendable_internal_key(), cmr);
let blinder = None;
elements::Address::p2tr(
secp256k1::SECP256K1,
Expand Down