SNARK-friendly STM: jubjub wrapper

mithril-stm/CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.8.1 (12-22-2025)
+
+### Added
+
+- Jubjub wrapper is added for `schnorr_signature` module.
+
 ## 0.8.0 (12-17-2025)
 
 ### Changed

mithril-stm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mithril-stm"
-version = "0.8.0"
+version = "0.8.1"
 edition = { workspace = true }
 authors = { workspace = true }
 homepage = { workspace = true }

mithril-stm/benches/schnorr_sig.rs

@@ -45,8 +45,8 @@ fn sign_and_verify(c: &mut Criterion, nr_sigs: usize) {
     let mut msks = Vec::new();
     let mut sigs = Vec::new();
     for _ in 0..nr_sigs {
-        let sk = SchnorrSigningKey::try_generate(&mut rng).unwrap();
-        let vk = SchnorrVerificationKey::from(&sk);
+        let sk = SchnorrSigningKey::generate(&mut rng).unwrap();
+        let vk = SchnorrVerificationKey::new_from_signing_key(sk.clone()).unwrap();
         let sig = sk.sign(&msg, &mut rng_sig).unwrap();
         sigs.push(sig);
         mvks.push(vk);

mithril-stm/src/signature_scheme/schnorr_signature/error.rs

@@ -1,5 +1,5 @@
 #[cfg(feature = "future_snark")]
-use super::{SchnorrSignature, SchnorrVerificationKey};
+use super::{PrimeOrderProjectivePoint, SchnorrSignature};
 
 /// Error types for Schnorr signatures.
 #[cfg(feature = "future_snark")]
@@ -9,19 +9,35 @@ pub enum SchnorrSignatureError {
     #[error("Invalid Schnorr single signature")]
     SignatureInvalid(Box<SchnorrSignature>),
 
-    /// Invalid Verification key
-    #[error("Invalid Schnorr Verification key")]
-    VerificationKeyInvalid(Box<SchnorrVerificationKey>),
-
     /// This error occurs when the serialization of the raw bytes failed
     #[error("Invalid bytes")]
-    SerializationError,
+    Serialization,
+
+    /// This error occurs when the serialization of the scalar field bytes failed
+    #[error("Invalid scalar field element bytes")]
+    ScalarFieldElementSerialization,
+
+    /// This error occurs when the serialization of the projective point bytes failed
+    #[error("Invalid projective point bytes")]
+    ProjectivePointSerialization,
 
-    /// This error occurs when the signing key fails to generate
-    #[error("Failed generation of the signing key")]
-    SigningKeyGenerationError,
+    /// This error occurs when the serialization of the prime order projective point bytes failed
+    #[error("Invalid prime order projective point bytes")]
+    PrimeOrderProjectivePointSerialization,
 
     /// This error occurs when the random scalar fails to generate during the signature
     #[error("Failed generation of the signature's random scalar")]
-    RandomScalarGenerationError,
+    RandomScalarGeneration,
+
+    /// This error occurs when signing key is zero or one.
+    #[error("The signing key is invalid.")]
+    InvalidSigningKey,
+
+    /// Given point is not on the curve
+    #[error("Given point is not on the curve")]
+    PointIsNotOnCurve(Box<PrimeOrderProjectivePoint>),
+
+    /// Given point is not prime order
+    #[error("Given point is not prime order")]
+    PointIsNotPrimeOrder(Box<PrimeOrderProjectivePoint>),
 }