add secp256k1 ciphersuite (#175)

* add secp256k1 ciphersuite * use workaround for hash2field * fix secp256k1 docs caused by gendoc bug * Apply suggestions from code review Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com> * removed random_nonzero which is no longer needed * typo * cargo fmt * rustdoc url Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
2022-11-22 18:09:21 -03:00 · 2022-11-22 18:09:21 -03:00 · 3e1fe25dbd
parent 1815280576
commit 3e1fe25dbd
9 changed files with 717 additions and 2 deletions
--- a/Cargo.toml
+++ b/Cargo.toml
@ -3,8 +3,9 @@ resolver = "2"
 members = [
    "frost-core",
    #"frost-redjubjub",
-    "frost-ristretto255",
-    "frost-p256",
    "frost-ed25519",
+    "frost-p256",
+    "frost-ristretto255",
+    "frost-secp256k1",
    "gendoc"
 ]
--- a/frost-secp256k1/Cargo.toml
+++ b/frost-secp256k1/Cargo.toml
@ -0,0 +1,48 @@
+[package]
+name = "frost-secp256k1"
+edition = "2021"
+# When releasing to crates.io:
+# - Update html_root_url
+# - Update CHANGELOG.md
+# - Create git tag.
+version = "0.1.0"
+authors = ["Deirdre Connolly <durumcrustulum@gmail.com>", "Chelsea Komlo <me@chelseakomlo.com>",
+    "Conrado Gouvea <conradoplg@gmail.com>"]
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/ZcashFoundation/frost"
+categories = ["cryptography"]
+keywords = ["cryptography", "crypto", "ristretto", "threshold", "signature"]
+description = "A Schnorr signature scheme over the prime-order Ristretto group that supports FROST ."
+
+[package.metadata.docs.rs]
+features = ["nightly"]
+
+[dependencies]
+byteorder = "1.4"
+digest = "0.10"
+frost-core = { path = "../frost-core", features = ["test-impl"] }
+hex = { version = "0.4.3", features = ["serde"] }
+# k256 = { version = "0.11.6", features = ["arithmetic", "hash2curve"] }
+k256 = { git = "https://github.com/RustCrypto/elliptic-curves", rev = "42a18e9e13f3bacba89af00d15ef732dbfd03d01", features = ["arithmetic", "hash2curve"] }
+rand_core = "0.6"
+serde = { version = "1", optional = true, features = ["derive"] }
+sha2 = "0.10.2"
+thiserror = "1.0"
+zeroize = { version = "1", default-features = false, features = ["zeroize_derive"] }
+
+[dev-dependencies]
+bincode = "1"
+criterion = "0.4"
+ed25519-dalek = "1.0.1"
+ed25519-zebra = "3.0.0"
+lazy_static = "1.4"
+proptest = "1.0"
+proptest-derive = "0.3"
+rand = "0.8"
+rand_chacha = "0.3"
+serde_json = "1.0"
+
+[features]
+nightly = []
+default = ["serde"]
--- a/frost-secp256k1/README.md
+++ b/frost-secp256k1/README.md
@ -0,0 +1,98 @@
+An implementation of Schnorr signatures on the secp256k1 curve for both single and threshold numbers
+of signers (FROST).
+
+## Example: key generation with trusted dealer and FROST signing
+
+Creating a key with a trusted dealer and splitting into shares; then signing a message
+and aggregating the signature. Note that the example just simulates a distributed
+scenario in a single thread and it abstracts away any communication between peers.
+
+
+```rust
+use frost_secp256k1 as frost;
+use rand::thread_rng;
+use std::collections::HashMap;
+
+let mut rng = thread_rng();
+let max_signers = 5;
+let min_signers = 3;
+let (shares, pubkeys) = frost::keys::keygen_with_dealer(max_signers, min_signers, &mut rng)?;
+
+// Verifies the secret shares from the dealer and store them in a HashMap.
+// In practice, the KeyPackages must be sent to its respective participants
+// through a confidential and authenticated channel.
+let key_packages: HashMap<_, _> = shares
+    .into_iter()
+    .map(|share| Ok((share.identifier, frost::keys::KeyPackage::try_from(share)?)))
+    .collect::<Result<_, _>>()?;
+
+let mut nonces = HashMap::new();
+let mut commitments = HashMap::new();
+
+////////////////////////////////////////////////////////////////////////////
+// Round 1: generating nonces and signing commitments for each participant
+////////////////////////////////////////////////////////////////////////////
+
+// In practice, each iteration of this loop will be executed by its respective participant.
+for participant_index in 1..(min_signers as u16 + 1) {
+    let participant_identifier = participant_index.try_into().expect("should be nonzero");
+    // Generate one (1) nonce and one SigningCommitments instance for each
+    // participant, up to _threshold_.
+    let (nonce, commitment) = frost::round1::commit(
+        participant_identifier,
+        key_packages[&participant_identifier].secret_share(),
+        &mut rng,
+    );
+    // In practice, the nonces and commitment must be sent to the coordinator
+    // (or to every other participant if there is no coordinator) using
+    // an authenticated channel.
+    nonces.insert(participant_identifier, nonce);
+    commitments.insert(participant_identifier, commitment);
+}
+
+// This is what the signature aggregator / coordinator needs to do:
+// - decide what message to sign
+// - take one (unused) commitment per signing participant
+let mut signature_shares = Vec::new();
+let message = "message to sign".as_bytes();
+let comms = commitments.clone().into_values().collect();
+// In practice, the SigningPackage must be sent to all participants
+// involved in the current signing (at least min_signers participants),
+// using an authenticate channel (and confidential if the message is secret).
+let signing_package = frost::SigningPackage::new(comms, message.to_vec());
+
+////////////////////////////////////////////////////////////////////////////
+// Round 2: each participant generates their signature share
+////////////////////////////////////////////////////////////////////////////
+
+// In practice, each iteration of this loop will be executed by its respective participant.
+for participant_identifier in nonces.keys() {
+    let key_package = &key_packages[participant_identifier];
+
+    let nonces_to_use = &nonces[participant_identifier];
+
+    // Each participant generates their signature share.
+    let signature_share = frost::round2::sign(&signing_package, nonces_to_use, key_package)?;
+
+    // In practice, the signature share must be sent to the Coordinator
+    // using an authenticated channel.
+    signature_shares.push(signature_share);
+}
+
+////////////////////////////////////////////////////////////////////////////
+// Aggregation: collects the signing shares from all participants,
+// generates the final signature.
+////////////////////////////////////////////////////////////////////////////
+
+// Aggregate (also verifies the signature shares)
+let group_signature = frost::aggregate(&signing_package, &signature_shares[..], &pubkeys)?;
+
+// Check that the threshold signature can be verified by the group public
+// key (the verification key).
+assert!(pubkeys
+    .group_public
+    .verify(message, &group_signature)
+    .is_ok());
+
+# Ok::<(), frost::Error>(())
+```
--- a/frost-secp256k1/src/lib.rs
+++ b/frost-secp256k1/src/lib.rs
@ -0,0 +1,386 @@
+#![allow(non_snake_case)]
+#![deny(missing_docs)]
+#![doc = include_str!("../README.md")]
+
+use digest::generic_array::GenericArray;
+use k256::{
+    elliptic_curve::{
+        bigint::{Encoding, U384},
+        group::prime::PrimeCurveAffine,
+        hash2curve::{ExpandMsg, ExpandMsgXmd, Expander},
+        sec1::{FromEncodedPoint, ToEncodedPoint},
+        Field as FFField, PrimeField,
+    },
+    AffinePoint, ProjectivePoint, Scalar,
+};
+use rand_core::{CryptoRng, RngCore};
+use sha2::{digest::Update, Digest, Sha256};
+
+use frost_core::{frost, Ciphersuite, Field, Group};
+
+#[cfg(test)]
+mod tests;
+
+pub use frost_core::Error;
+
+#[derive(Clone, Copy)]
+/// An implementation of the FROST(secp256k1, SHA-256) ciphersuite scalar field.
+pub struct Secp256K1ScalarField;
+
+impl Field for Secp256K1ScalarField {
+    type Scalar = Scalar;
+
+    type Serialization = [u8; 32];
+
+    fn zero() -> Self::Scalar {
+        Scalar::ZERO
+    }
+
+    fn one() -> Self::Scalar {
+        Scalar::ONE
+    }
+
+    fn invert(scalar: &Self::Scalar) -> Result<Self::Scalar, Error> {
+        // [`Scalar`]'s Eq/PartialEq does a constant-time comparison
+        if *scalar == <Self as Field>::zero() {
+            Err(Error::InvalidZeroScalar)
+        } else {
+            Ok(scalar.invert().unwrap())
+        }
+    }
+
+    fn random<R: RngCore + CryptoRng>(rng: &mut R) -> Self::Scalar {
+        Scalar::random(rng)
+    }
+
+    fn serialize(scalar: &Self::Scalar) -> Self::Serialization {
+        scalar.to_bytes().into()
+    }
+
+    fn deserialize(buf: &Self::Serialization) -> Result<Self::Scalar, Error> {
+        let field_bytes: &k256::FieldBytes = buf.into();
+        match Scalar::from_repr(*field_bytes).into() {
+            Some(s) => Ok(s),
+            None => Err(Error::MalformedScalar),
+        }
+    }
+
+    fn little_endian_serialize(scalar: &Self::Scalar) -> Self::Serialization {
+        let mut array = Self::serialize(scalar);
+        array.reverse();
+        array
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+/// An implementation of the FROST(secp256k1, SHA-256) ciphersuite group.
+pub struct Secp256K1Group;
+
+impl Group for Secp256K1Group {
+    type Field = Secp256K1ScalarField;
+
+    type Element = ProjectivePoint;
+
+    /// [SEC 1][1] serialization of a compressed point in secp256k1 takes 33 bytes
+    /// (1-byte prefix and 32 bytes for the coordinate).
+    ///
+    /// Note that, in the SEC 1 spec, the identity is encoded as a single null byte;
+    /// but here we pad with zeroes. This is acceptable as the identity _should_ never
+    /// be serialized in FROST, else we error.
+    ///
+    /// [1]: https://secg.org/sec1-v2.pdf
+    type Serialization = [u8; 33];
+
+    fn cofactor() -> <Self::Field as Field>::Scalar {
+        Scalar::one()
+    }
+
+    fn identity() -> Self::Element {
+        ProjectivePoint::IDENTITY
+    }
+
+    fn generator() -> Self::Element {
+        ProjectivePoint::GENERATOR
+    }
+
+    fn serialize(element: &Self::Element) -> Self::Serialization {
+        let mut fixed_serialized = [0; 33];
+        let serialized_point = element.to_affine().to_encoded_point(true);
+        let serialized = serialized_point.as_bytes();
+        // Sanity check; either it takes all bytes or a single byte (identity).
+        assert!(serialized.len() == fixed_serialized.len() || serialized.len() == 1);
+
+        // Copy to the left of the buffer (i.e. pad the identity with zeroes).
+        // TODO: Note that identity elements shouldn't be serialized in FROST. This will likely become
+        // part of the API and when that happens, we should return an error instead of
+        // doing this padding.
+        {
+            let (left, _right) = fixed_serialized.split_at_mut(serialized.len());
+            left.copy_from_slice(serialized);
+        }
+        fixed_serialized
+    }
+
+    fn deserialize(buf: &Self::Serialization) -> Result<Self::Element, Error> {
+        let encoded_point =
+            k256::EncodedPoint::from_bytes(buf).map_err(|_| Error::MalformedElement)?;
+
+        match Option::<AffinePoint>::from(AffinePoint::from_encoded_point(&encoded_point)) {
+            Some(point) => {
+                if point.is_identity().into() {
+                    // This is actually impossible since the identity is encoded a a single byte
+                    // which will never happen since we receive a 33-byte buffer.
+                    // We leave the check for consistency.
+                    Err(Error::InvalidIdentityElement)
+                } else {
+                    Ok(ProjectivePoint::from(point))
+                }
+            }
+            None => Err(Error::MalformedElement),
+        }
+    }
+}
+
+/// hash2field implementation from <https://tools.ietf.org/html/draft-irtf-cfrg-hash-to-curve-11#section-5.3>
+///
+/// From <https://github.com/serai-dex/serai/blob/5df74ac9e28f9299e674e98d08e64c99c34e579c/crypto/ciphersuite/src/kp256.rs#L45-L62>
+//
+// After https://github.com/RustCrypto/elliptic-curves/pull/673/ merges this should
+// be removed, and a similar implementation to p256 should be used.
+fn hash_to_field(msg: &[u8], dst: &[u8]) -> Scalar {
+    let mut modulus = [0; 48];
+    modulus[16..].copy_from_slice(&(Scalar::ZERO - Scalar::ONE).to_bytes());
+    let modulus = U384::from_be_slice(&modulus).wrapping_add(&U384::ONE);
+
+    let unreduced = U384::from_be_bytes({
+        let mut bytes = [0; 48];
+        ExpandMsgXmd::<Sha256>::expand_message(&[msg], dst, 48)
+            .expect("should never return error according to error cases described in ExpandMsgXmd")
+            .fill_bytes(&mut bytes);
+        bytes
+    })
+    .reduce(&modulus)
+    .unwrap()
+    .to_be_bytes();
+
+    let array = *GenericArray::from_slice(&unreduced[16..]);
+    Scalar::from_repr(array).unwrap()
+}
+
+/// Context string from the ciphersuite in the [spec].
+///
+/// [spec]: https://www.ietf.org/archive/id/draft-irtf-cfrg-frost-11.html#section-6.5-1
+const CONTEXT_STRING: &str = "FROST-secp256k1-SHA256-v11";
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+/// An implementation of the FROST(secp256k1, SHA-256) ciphersuite.
+pub struct Secp256K1Sha256;
+
+impl Ciphersuite for Secp256K1Sha256 {
+    type Group = Secp256K1Group;
+
+    type HashOutput = [u8; 32];
+
+    type SignatureSerialization = [u8; 65];
+
+    /// H1 for FROST(secp256k1, SHA-256)
+    ///
+    /// [spec]: https://www.ietf.org/archive/id/draft-irtf-cfrg-frost-11.html#section-6.5-2.2.2.1
+    fn H1(m: &[u8]) -> <<Self::Group as Group>::Field as Field>::Scalar {
+        let dst = CONTEXT_STRING.to_owned() + "rho";
+        hash_to_field(m, dst.as_bytes())
+    }
+
+    /// H2 for FROST(secp256k1, SHA-256)
+    ///
+    /// [spec]: https://www.ietf.org/archive/id/draft-irtf-cfrg-frost-11.html#section-6.5-2.2.2.2
+    fn H2(m: &[u8]) -> <<Self::Group as Group>::Field as Field>::Scalar {
+        let dst = CONTEXT_STRING.to_owned() + "chal";
+        hash_to_field(m, dst.as_bytes())
+    }
+
+    /// H3 for FROST(secp256k1, SHA-256)
+    ///
+    /// [spec]: https://www.ietf.org/archive/id/draft-irtf-cfrg-frost-11.html#section-6.5-2.2.2.3
+    fn H3(m: &[u8]) -> <<Self::Group as Group>::Field as Field>::Scalar {
+        let dst = CONTEXT_STRING.to_owned() + "nonce";
+        hash_to_field(m, dst.as_bytes())
+    }
+
+    /// H4 for FROST(secp256k1, SHA-256)
+    ///
+    /// [spec]: https://www.ietf.org/archive/id/draft-irtf-cfrg-frost-11.html#section-6.5-2.2.2.4
+    fn H4(m: &[u8]) -> Self::HashOutput {
+        let h = Sha256::new()
+            .chain(CONTEXT_STRING.as_bytes())
+            .chain("msg")
+            .chain(m);
+
+        let mut output = [0u8; 32];
+        output.copy_from_slice(h.finalize().as_slice());
+        output
+    }
+
+    /// H5 for FROST(secp256k1, SHA-256)
+    ///
+    /// [spec]: https://www.ietf.org/archive/id/draft-irtf-cfrg-frost-11.html#section-6.5-2.2.2.5
+    fn H5(m: &[u8]) -> Self::HashOutput {
+        let h = Sha256::new()
+            .chain(CONTEXT_STRING.as_bytes())
+            .chain("com")
+            .chain(m);
+
+        let mut output = [0u8; 32];
+        output.copy_from_slice(h.finalize().as_slice());
+        output
+    }
+
+    /// HDKG for FROST(secp256k1, SHA-256)
+    fn HDKG(m: &[u8]) -> Option<<<Self::Group as Group>::Field as Field>::Scalar> {
+        let dst = CONTEXT_STRING.to_owned() + "dkg";
+        Some(hash_to_field(m, dst.as_bytes()))
+    }
+}
+
+type R = Secp256K1Sha256;
+
+/// A FROST(secp256k1, SHA-256) participant identifier.
+pub type Identifier = frost::Identifier<R>;
+
+/// FROST(secp256k1, SHA-256) keys, key generation, key shares.
+pub mod keys {
+    use super::*;
+
+    /// Allows all participants' keys to be generated using a central, trusted
+    /// dealer.
+    pub fn keygen_with_dealer<RNG: RngCore + CryptoRng>(
+        max_signers: u16,
+        min_signers: u16,
+        mut rng: RNG,
+    ) -> Result<(Vec<SecretShare>, PublicKeyPackage), Error> {
+        frost::keys::keygen_with_dealer(max_signers, min_signers, &mut rng)
+    }
+
+    /// Secret and public key material generated by a dealer performing
+    /// [`keygen_with_dealer`].
+    ///
+    /// # Security
+    ///
+    /// To derive a FROST(secp256k1, SHA-256) keypair, the receiver of the [`SecretShare`] *must* call
+    /// .into(), which under the hood also performs validation.
+    pub type SecretShare = frost::keys::SecretShare<R>;
+
+    /// A FROST(secp256k1, SHA-256) keypair, which can be generated either by a trusted dealer or using
+    /// a DKG.
+    ///
+    /// When using a central dealer, [`SecretShare`]s are distributed to
+    /// participants, who then perform verification, before deriving
+    /// [`KeyPackage`]s, which they store to later use during signing.
+    pub type KeyPackage = frost::keys::KeyPackage<R>;
+
+    /// Public data that contains all the signers' public keys as well as the
+    /// group public key.
+    ///
+    /// Used for verification purposes before publishing a signature.
+    pub type PublicKeyPackage = frost::keys::PublicKeyPackage<R>;
+}
+
+/// FROST(secp256k1, SHA-256) Round 1 functionality and types.
+pub mod round1 {
+    use frost_core::frost::keys::SigningShare;
+
+    use super::*;
+
+    /// Comprised of FROST(secp256k1, SHA-256) hiding and binding nonces.
+    ///
+    /// Note that [`SigningNonces`] must be used *only once* for a signing
+    /// operation; re-using nonces will result in leakage of a signer's long-lived
+    /// signing key.
+    pub type SigningNonces = frost::round1::SigningNonces<R>;
+
+    /// Published by each participant in the first round of the signing protocol.
+    ///
+    /// This step can be batched if desired by the implementation. Each
+    /// SigningCommitment can be used for exactly *one* signature.
+    pub type SigningCommitments = frost::round1::SigningCommitments<R>;
+
+    /// Performed once by each participant selected for the signing operation.
+    ///
+    /// Generates the signing nonces and commitments to be used in the signing
+    /// operation.
+    pub fn commit<RNG>(
+        participant_identifier: frost::Identifier<R>,
+        secret: &SigningShare<R>,
+        rng: &mut RNG,
+    ) -> (SigningNonces, SigningCommitments)
+    where
+        RNG: CryptoRng + RngCore,
+    {
+        frost::round1::commit::<R, RNG>(participant_identifier, secret, rng)
+    }
+}
+
+/// Generated by the coordinator of the signing operation and distributed to
+/// each signing party.
+pub type SigningPackage = frost::SigningPackage<R>;
+
+/// FROST(secp256k1, SHA-256) Round 2 functionality and types, for signature share generation.
+pub mod round2 {
+    use super::*;
+
+    /// A FROST(secp256k1, SHA-256) participant's signature share, which the Coordinator will aggregate with all other signer's
+    /// shares into the joint signature.
+    pub type SignatureShare = frost::round2::SignatureShare<R>;
+
+    /// Generated by the coordinator of the signing operation and distributed to
+    /// each signing party
+    pub type SigningPackage = frost::SigningPackage<R>;
+
+    /// Performed once by each participant selected for the signing operation.
+    ///
+    /// Receives the message to be signed and a set of signing commitments and a set
+    /// of randomizing commitments to be used in that signing operation, including
+    /// that for this participant.
+    ///
+    /// Assumes the participant has already determined which nonce corresponds with
+    /// the commitment that was assigned by the coordinator in the SigningPackage.
+    pub fn sign(
+        signing_package: &SigningPackage,
+        signer_nonces: &round1::SigningNonces,
+        key_package: &keys::KeyPackage,
+    ) -> Result<SignatureShare, Error> {
+        frost::round2::sign(signing_package, signer_nonces, key_package)
+    }
+}
+
+/// A Schnorr signature on FROST(secp256k1, SHA-256).
+pub type Signature = frost_core::Signature<R>;
+
+/// Verifies each FROST(secp256k1, SHA-256) participant's signature share, and if all are valid,
+/// aggregates the shares into a signature to publish.
+///
+/// Resulting signature is compatible with verification of a plain Schnorr
+/// signature.
+///
+/// This operation is performed by a coordinator that can communicate with all
+/// the signing participants before publishing the final signature. The
+/// coordinator can be one of the participants or a semi-trusted third party
+/// (who is trusted to not perform denial of service attacks, but does not learn
+/// any secret information). Note that because the coordinator is trusted to
+/// report misbehaving parties in order to avoid publishing an invalid
+/// signature, if the coordinator themselves is a signer and misbehaves, they
+/// can avoid that step. However, at worst, this results in a denial of
+/// service attack due to publishing an invalid signature.
+pub fn aggregate(
+    signing_package: &round2::SigningPackage,
+    signature_shares: &[round2::SignatureShare],
+    pubkeys: &keys::PublicKeyPackage,
+) -> Result<Signature, Error> {
+    frost::aggregate(signing_package, signature_shares, pubkeys)
+}
+
+/// A signing key for a Schnorr signature on FROST(secp256k1, SHA-256).
+pub type SigningKey = frost_core::SigningKey<R>;
+
+/// A valid verifying key for Schnorr signatures on FROST(secp256k1, SHA-256).
+pub type VerifyingKey = frost_core::VerifyingKey<R>;
--- a/frost-secp256k1/src/tests.rs
+++ b/frost-secp256k1/src/tests.rs
@ -0,0 +1,24 @@
+use lazy_static::lazy_static;
+use rand::thread_rng;
+use serde_json::Value;
+
+use crate::*;
+
+lazy_static! {
+    pub static ref SECP256K1_SHA256: Value =
+        serde_json::from_str(include_str!("tests/vectors.json").trim())
+            .expect("Test vector is valid JSON");
+}
+
+/// This is testing that Shamir's secret sharing to compute and arbitrary
+/// value is working.
+#[test]
+fn check_share_generation_secp256k1_sha256() {
+    let rng = thread_rng();
+    frost_core::tests::check_share_generation::<Secp256K1Sha256, _>(rng);
+}
+
+#[test]
+fn check_sign_with_test_vectors() {
+    frost_core::tests::vectors::check_sign_with_test_vectors::<Secp256K1Sha256>(&SECP256K1_SHA256)
+}
--- a/frost-secp256k1/src/tests/vectors.json
+++ b/frost-secp256k1/src/tests/vectors.json
@ -0,0 +1,68 @@
+{
+  "config": {
+    "MAX_PARTICIPANTS": "3",
+    "NUM_PARTICIPANTS": "2",
+    "MIN_PARTICIPANTS": "2",
+    "name": "FROST(secp256k1, SHA-256)",
+    "group": "secp256k1",
+    "hash": "SHA-256"
+  },
+  "inputs": {
+    "group_secret_key": "0d004150d27c3bf2a42f312683d35fac7394b1e9e318249c1bfe7f0795a83114",
+    "group_public_key": "02f37c34b66ced1fb51c34a90bdae006901f10625cc06c4f64663b0eae87d87b4f",
+    "message": "74657374",
+    "share_polynomial_coefficients": [
+      "fbf85eadae3058ea14f19148bb72b45e4399c0b16028acaf0395c9b03c823579"
+    ],
+    "participants": {
+      "1": {
+        "participant_share": "08f89ffe80ac94dcb920c26f3f46140bfc7f95b493f8310f5fc1ea2b01f4254c"
+      },
+      "2": {
+        "participant_share": "04f0feac2edcedc6ce1253b7fab8c86b856a797f44d83d82a385554e6e401984"
+      },
+      "3": {
+        "participant_share": "00e95d59dd0d46b0e303e500b62b7ccb0e555d49f5b849f5e748c071da8c0dbc"
+      }
+    }
+  },
+  "round_one_outputs": {
+    "participant_list": "1,3",
+    "participants": {
+      "1": {
+        "hiding_nonce_randomness": "80cbea5e405d169999d8c4b30b755fedb26ab07ec8198cda4873ed8ce5e16773",
+        "binding_nonce_randomness": "f6d5b38197843046b68903048c1feba433e3500145281fa8bb1e26fdfeef5e7f",
+        "hiding_nonce": "acc83278035223c1ba464e2d11bfacfc872b2b23e1041cf5f6130da21e4d8068",
+        "binding_nonce": "c3ef169995bc3d2c2d48f30b83d0c63751e67ceb057695bcb2a6aa40ed5d926b",
+        "hiding_nonce_commitment": "036673d68a928793c33ae07776908eae8ea15dd947ed81284e939aaba118573a5e",
+        "binding_nonce_commitment": "03d2a96dd4ec1ee29dc22067109d1290dabd8016cb41856ee8ff9281c3fa1baffd",
+        "binding_factor_input": "a645d8249457bbcac34fa7b740f66bcce08fc39506b8bbf1a1c81092f6272eda82ae39234d714f87a7b91dd67d124a06561a36817c1ecaa255c3527d694fc4f10000000000000000000000000000000000000000000000000000000000000001",
+        "binding_factor": "d7bcbd29408dedc9e138262d99b09d8b5705d76eb5de2369d9103e4423f8ac79"
+      },
+      "3": {
+        "hiding_nonce_randomness": "b9794047604beda0c5c0529ac9dfd83c0a80399a7bdf4c3e23cef2faf69cdcc3",
+        "binding_nonce_randomness": "c28ce6252631620b84c2702b34774fab365e286ebc77030a112ebccccbffa78b",
+        "hiding_nonce": "cb3387defef07fc9010c0564ba6495ed41876626ed86b886ca26cbbd3566ffbc",
+        "binding_nonce": "4559459735eb68e8c16319a9fd9a14016053957cb8cea273a24b7c7bc1ee26f6",
+        "hiding_nonce_commitment": "030278e6e6055fb963b40e0c3c37099f803f3f38930fc89092517f8ce1b47e8d6b",
+        "binding_nonce_commitment": "028eb6d238c6c0fc6216906706ad0ff9943c6c1d6079cdf74f674481ebb2485db3",
+        "binding_factor_input": "a645d8249457bbcac34fa7b740f66bcce08fc39506b8bbf1a1c81092f6272eda82ae39234d714f87a7b91dd67d124a06561a36817c1ecaa255c3527d694fc4f10000000000000000000000000000000000000000000000000000000000000003",
+        "binding_factor": "ecc057259f3c8b195308c9b73aaaf840660a37eb264ebce342412c58102ee437"
+      }
+    }
+  },
+  "round_two_outputs": {
+    "participant_list": "1,3",
+    "participants": {
+      "1": {
+        "sig_share": "1750b2a314a81b66fd81366583617aaafcffa68f14495204795aa0434b907aa3"
+      },
+      "3": {
+        "sig_share": "e4dbbbbbcb035eb3512918b0368c4ab2c836a92dccff3251efa7a4aacc7d3790"
+      }
+    }
+  },
+  "final_output": {
+    "sig": "0259696aac722558e8638485d252bb2556f6241a7adfdf284c8c87a3428d46448dfc2c6e5edfab7a1a4eaa4f15b9edc55dc5364fbce1488456690244ee180db233"
+  }
+}
--- a/frost-secp256k1/tests/frost.rs
+++ b/frost-secp256k1/tests/frost.rs
@ -0,0 +1,41 @@
+use frost_core::{Ciphersuite, Group};
+use frost_secp256k1::*;
+use rand::thread_rng;
+
+#[test]
+fn check_sign_with_dealer() {
+    let rng = thread_rng();
+
+    frost_core::tests::check_sign_with_dealer::<Secp256K1Sha256, _>(rng);
+}
+
+#[test]
+fn check_sign_with_dkg() {
+    let rng = thread_rng();
+
+    frost_core::tests::check_sign_with_dkg::<Secp256K1Sha256, _>(rng);
+}
+
+#[test]
+fn check_batch_verify() {
+    let rng = thread_rng();
+
+    frost_core::tests::batch::batch_verify::<Secp256K1Sha256, _>(rng);
+}
+
+#[test]
+fn check_bad_batch_verify() {
+    let rng = thread_rng();
+
+    frost_core::tests::batch::bad_batch_verify::<Secp256K1Sha256, _>(rng);
+}
+
+#[test]
+fn check_deserialize_identity() {
+    // The identity is actually encoded as a single byte; but the API does not
+    // allow us to change that. Try to send something similar.
+    let encoded_identity = [0u8; 33];
+
+    let r = <<Secp256K1Sha256 as Ciphersuite>::Group as Group>::deserialize(&encoded_identity);
+    assert_eq!(r, Err(Error::MalformedElement));
+}
--- a/frost-secp256k1/tests/proptests.rs
+++ b/frost-secp256k1/tests/proptests.rs
@ -0,0 +1,33 @@
+use frost_core::tests::proptests::{tweak_strategy, SignatureCase};
+use frost_secp256k1::*;
+use proptest::prelude::*;
+
+use rand_chacha::ChaChaRng;
+use rand_core::SeedableRng;
+
+proptest! {
+
+    #[test]
+    fn tweak_signature(
+        tweaks in prop::collection::vec(tweak_strategy(), (0,5)),
+        rng_seed in prop::array::uniform32(any::<u8>()),
+    ) {
+        // Use a deterministic RNG so that test failures can be reproduced.
+        // Seeding with 64 bits of entropy is INSECURE and this code should
+        // not be copied outside of this test!
+        let mut rng = ChaChaRng::from_seed(rng_seed);
+
+        // Create a test case for each signature type.
+        let msg = b"test message for proptests";
+        let mut sig = SignatureCase::<Secp256K1Sha256>::new(&mut rng, msg.to_vec());
+
+        // Apply tweaks to each case.
+        for t in &tweaks {
+            sig.apply_tweak(t);
+        }
+
+        assert!(sig.check());
+    }
+
+
+}
--- a/gendoc/src/main.rs
+++ b/gendoc/src/main.rs
@ -168,4 +168,20 @@ fn main() {
            &["frost_ed25519", "Ed25519 curve"],
        );
    }
+
+    write_docs(
+        &docs,
+        "frost-secp256k1/src/lib.rs",
+        &["Secp256K1Sha556", "Secp256K1", "<E>"],
+        old_suite_names_doc,
+        &["FROST(secp256k1, SHA-256)"],
+    );
+    for filename in ["README.md", "dkg.md"] {
+        copy_and_replace(
+            filename,
+            "frost-secp256k1/README.md",
+            original_strings,
+            &["frost_secp256k1", "secp256k1 curve"],
+        );
+    }
 }