chore: code organization changes

Author: manishbista28

Cargo.lock

@@ -48,6 +48,7 @@ rustdoc.all = "warn"
 clippy.too_long_first_doc_paragraph = "warn"
 
 [workspace.dependencies]
+mosaic-adaptor-sigs = { path = "crates/adaptor-sigs" }
 mosaic-cac-proto-types = { path = "crates/cac/proto-types" }
 mosaic-cac-protocol = { path = "crates/cac/protocol" }
 mosaic-cac-types = { path = "crates/cac/types" }
@@ -68,13 +69,20 @@ ark-ec = "0.5.0"
 ark-ff = "0.5.0"
 ark-secp256k1 = "0.5.0"
 async-trait = "0.1"
+bitcoin = { version = "0.32.7", features = ["rand", "rand-std"] }
+bitcoin-script = { git = "https://github.com/BitVM/rust-bitcoin-script" }
+bitcoin-scriptexec = { git = "https://github.com/BitVM/rust-bitcoin-scriptexec" }
 bytes = "1.10"
+once_cell = "1.21.3"
 futures = "0.3.31"
 jsonrpsee = { version = "0.26.0", features = ["macros"] }
 jsonrpsee-types = "*"                                                       # constrained by jsonrpsee dep
+k256 = "0.13.4"
 rand = "0.8"
+rand_chacha = "0.3.0"
 rand_core = "0.6"
 serde = { version = "1.0", features = ["derive"] }
+sha2 = "0.10"
 strata-codec = { git = "https://github.com/alpenlabs/strata-common.git" }
 thiserror = "2.0"
 tokio = { version = "1.48.0", features = ["rt", "sync", "macros", "time"] }

Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "adaptor-sigs"
+name = "mosaic-adaptor-sigs"
 version.workspace = true
 edition.workspace = true
 authors.workspace = true
@@ -14,17 +14,18 @@ keywords.workspace = true
 ark-ec.workspace = true
 ark-ff.workspace = true
 ark-secp256k1.workspace = true
-once_cell = "1.21.3"
+mosaic-common.workspace = true
+once_cell.workspace = true
 rand.workspace = true
-sha2 = "0.10"
+sha2.workspace = true
 thiserror.workspace = true
 
 [dev-dependencies]
-rand_chacha = "0.3.0"
-k256 = "0.13.4"
-bitcoin-script = { git = "https://github.com/BitVM/rust-bitcoin-script" }
-bitcoin-scriptexec = { git = "https://github.com/BitVM/rust-bitcoin-scriptexec" }
-bitcoin = { version = "0.32.7", features = ["rand", "rand-std"] }
+rand_chacha.workspace = true
+k256.workspace = true
+bitcoin.workspace = true
+bitcoin-script.workspace = true
+bitcoin-scriptexec.workspace = true
 
 [lints]
 workspace = true

crates/adaptor-sigs/Cargo.toml

@@ -20,8 +20,8 @@ use rand::{CryptoRng, Rng};
 use sha2::{Digest, Sha256};
 
 use crate::{error::Error, fixed_base::gen_mul};
-/* ------------------------------ Utilities --------------------------------- */
 
+/// Helpers to serialize and deserialize field as per BIP340
 fn serialize_field<F: PrimeField>(x: &F) -> [u8; 32] {
     // `Fq` modulus is 256 bits, so its big-endian encoding always fits in 32 bytes.
     x.into_bigint()
@@ -46,19 +46,6 @@ fn deserialize_field<F: PrimeField>(bytes: [u8; 32]) -> Result<F, Error> {
     ))
 }
 
-/* --------------------------------- Types ---------------------------------- */
-
-/// Adaptor for the VSSS
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Adaptor {
-    /// s' = ±r' + e * x  (the evaluator’s partial Schnorr s)
-    pub tweaked_s: ark_secp256k1::Fr,
-    /// R' = r'*G
-    pub R_dash_commit: ark_secp256k1::Projective,
-    /// S = share*G
-    pub share_commitment: ark_secp256k1::Projective,
-}
-
 /// Signature for the VSSS
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Signature {
@@ -93,28 +80,17 @@ impl Signature {
     }
 }
 
-/* ----------------------------- Challenge helper --------------------------- */
-
-/// e = H(BIP0340/challenge, R.x, P.x, wire_index, sighash)
-fn challenge_e(
-    R: ark_secp256k1::Affine,
-    P: ark_secp256k1::Affine,
-    sighash: &[u8],
-) -> ark_secp256k1::Fr {
-    // BIP340 tag
-    let tag_hash = Sha256::digest(b"BIP0340/challenge");
-    let mut h = Sha256::new();
-    h.update(tag_hash);
-    h.update(tag_hash);
-    h.update(serialize_field(&R.x));
-    h.update(serialize_field(&P.x));
-    h.update(sighash);
-    let digest = h.finalize();
-    ark_secp256k1::Fr::from_be_bytes_mod_order(&digest)
+/// Adaptor for the VSSS
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Adaptor {
+    /// s' = ±r' + e * x  (the evaluator’s partial Schnorr s)
+    pub tweaked_s: ark_secp256k1::Fr,
+    /// R' = r'*G
+    pub R_dash_commit: ark_secp256k1::Projective,
+    /// S = share*G
+    pub share_commitment: ark_secp256k1::Projective,
 }
 
-/* --------------------------------- Methods -------------------------------- */
-
 impl Adaptor {
     /// Generates an adaptor from the evaluator’s master secret key `x`, a commitment
     /// to the garbler’s share (`S = share·G`), and the `(wire_index, sighash)` transcript data.
@@ -161,7 +137,7 @@ impl Adaptor {
             ));
         }
 
-        let e = challenge_e(expected_R, evaluator_master_pk, sighash);
+        let e = Self::challenge_e(expected_R, evaluator_master_pk, sighash);
 
         if expected_R.y.into_bigint().is_odd() {
             // negate to make commitment of completed nonce (i.e. r_dash + share) even
@@ -207,7 +183,7 @@ impl Adaptor {
             ));
         }
 
-        let e = challenge_e(expected_R, evaluator_master_pk_affine, sighash);
+        let e = Self::challenge_e(expected_R, evaluator_master_pk_affine, sighash);
 
         // LHS: s'·G - e.P
         let lhs = gen_mul(&self.tweaked_s) - evaluator_master_pk * e;
@@ -262,6 +238,24 @@ impl Adaptor {
         let diff = signature.s - self.tweaked_s;
         if is_odd { -diff } else { diff }
     }
+
+    /// e = H(BIP0340/challenge, R.x, P.x, wire_index, sighash)
+    fn challenge_e(
+        R: ark_secp256k1::Affine,
+        P: ark_secp256k1::Affine,
+        sighash: &[u8],
+    ) -> ark_secp256k1::Fr {
+        // BIP340 tag
+        let tag_hash = Sha256::digest(b"BIP0340/challenge");
+        let mut h = Sha256::new();
+        h.update(tag_hash);
+        h.update(tag_hash);
+        h.update(serialize_field(&R.x));
+        h.update(serialize_field(&P.x));
+        h.update(sighash);
+        let digest = h.finalize();
+        ark_secp256k1::Fr::from_be_bytes_mod_order(&digest)
+    }
 }
 
 /* ---------------------------------- Tests ---------------------------------- */
@@ -463,7 +457,7 @@ mod tests {
         // Recompute e like verify() does
         let R = fx.adaptor.expected_R().into_affine();
         let P = fx.P.into_affine();
-        let e = super::challenge_e(R, P, &fx.sighash);
+        let e = Adaptor::challenge_e(R, P, &fx.sighash);
 
         let lhs = gen_mul(&fx.adaptor.tweaked_s); // s'·G
         let tweaked_R = if R.y.into_bigint().is_odd() {

crates/adaptor-sigs/src/adaptor.rs

@@ -2,11 +2,10 @@
 
 use ark_ec::{PrimeGroup, scalar_mul::BatchMulPreprocessing};
 use ark_secp256k1::{Fr as Scalar, Projective as Point};
+use mosaic_common::constants::{N_INPUT_WIRES, N_VERIFICAITON_CIRCUITS as N_COEFFICIENTS};
 use once_cell::sync::Lazy;
 
-use crate::{N_COEFFICIENTS, N_INPUT_WIRES};
-
-/// Heuristic, TODO optimize this
+/// TODO: @nakkstar123, @AaronFeickert: add comments on how this heuristic was designed
 const APPROX_MULS: usize = N_INPUT_WIRES * N_COEFFICIENTS * 3;
 
 /// Single global precomputation for G.

crates/adaptor-sigs/src/fixed_base.rs

@@ -1,12 +1,8 @@
 //! Mosaic adaptor signatures library.
 
-pub mod adaptor;
-pub mod error;
-pub(crate) mod fixed_base;
+mod adaptor;
+mod error;
+mod fixed_base;
 
-/// Number of coefficients in each polynomial.
-pub const N_COEFFICIENTS: usize = 174;
-/// Number of circuits (evaluation points).
-pub const N_SHARES: usize = 181;
-/// Number of input wires to the circuit.
-pub const N_INPUT_WIRES: usize = 1273;
+pub use adaptor::{Adaptor, Signature};
+pub use error::Error;

crates/adaptor-sigs/src/lib.rs

@@ -8,7 +8,7 @@ edition = "2024"
 cargo-fuzz = true
 
 [dependencies]
-adaptor-sigs = { path = "../crates/adaptor-sigs" }
+mosaic-adaptor-sigs = { path = "../crates/adaptor-sigs" }
 libfuzzer-sys = "0.4"
 k256 = "0.13.4"
 

fuzz/Cargo.lock

@@ -1,7 +1,7 @@
 #![no_main]
 
 use libfuzzer_sys::fuzz_target;
-use adaptor_sigs::adaptor::Signature;
+use mosaic_adaptor_sigs::Signature;
 
 fuzz_target!(|data: [u8; 64]| {
     // fuzzed code goes here