impl H2G for TE curves

CHANGELOG.md

@@ -13,6 +13,7 @@
 
 - Derive `Debug`, `Snafu` on `enum TaggedBlobError`
 - Updated `tagged-base64` reference url to reflect the Espresso Systems name change
+- Add `HashToGroup` support for both SW and TE curves
 
 ### Bugfixes
 

primitives/Cargo.toml

@@ -13,9 +13,12 @@ ark-ff = { version = "0.3.0", default-features = false }
 ark-std = { version = "0.3.0", default-features = false }
 ark-ec = { version = "0.3.0", default-features = false }
 ark-serialize = { version = "0.3.0", default-features = false }
+
+# ark curves
 ark-bls12-381 = { version = "0.3.0", default-features = false, features = ["curve"] }
 ark-bls12-377 = { git = "https://github.com/arkworks-rs/curves", default-features = false, features = ["curve"], rev = "677b4ae751a274037880ede86e9b6f30f62635af" }
-
+ark-ed-on-bls12-377 = { git = "https://github.com/arkworks-rs/curves", default-features = false, rev = "677b4ae751a274037880ede86e9b6f30f62635af"}
+ark-ed-on-bls12-381 = { version = "0.3.0", default-features = false }
 
 # jellyfish
 jf-plonk = { path = "../plonk" }
@@ -42,8 +45,6 @@ quickcheck = "1.0.0"
 criterion = "0.3.1"
 
 # ark curves
-ark-ed-on-bls12-377 = { git = "https://github.com/arkworks-rs/curves", default-features = false, rev = "677b4ae751a274037880ede86e9b6f30f62635af"}
-ark-ed-on-bls12-381 = { version = "0.3.0", default-features = false }
 ark-ed-on-bls12-381-bandersnatch = { git = "https://github.com/arkworks-rs/curves", default-features = false, rev = "677b4ae751a274037880ede86e9b6f30f62635af" }
 ark-ed-on-bn254 = { version = "0.3.0", default-features = false }
 ark-bn254 = { version = "0.3.0", default-features = false, features = ["curve"] }

primitives/src/hash_to_group/mod.rs

@@ -4,78 +4,10 @@
 // You should have received a copy of the MIT License
 // along with the Jellyfish library. If not, see <https://mit-license.org/>.
 
-//! Hash to Elliptic Curve implementation of <https://datatracker.ietf.org/doc/draft-irtf-cfrg-hash-to-curve/>
+//! Module for hash to various elliptic curve groups
 
-use ark_ec::{
-    short_weierstrass_jacobian::{GroupAffine, GroupProjective},
-    AffineCurve, SWModelParameters,
-};
-use ark_std::{
-    rand::{Rng, SeedableRng},
-    UniformRand,
-};
-use digest::Digest;
-use rand_chacha::ChaCha20Rng;
-use sha2::Sha256;
+mod short_weierstrass;
+mod twisted_edwards;
 
-use crate::errors::PrimitivesError;
-
-/// Trait definition and default implementation for hash to group functions.
-pub trait HashToGroup: SWModelParameters + Sized {
-    /// Hash to Group point, using sha2-512 function
-    /// hashing to G1 point of `C: ProjectiveCurve`.
-    // Default implementation implements a naive solution via rejection sampling.
-    // Slow, and non-constant time.
-    //
-    // For specific curves we may want to overload it with a more efficient
-    // algorithm, such as IETF BLS draft.
-    fn hash_to_group<B: AsRef<[u8]>>(
-        data: B,
-        cs_id: B,
-    ) -> Result<GroupProjective<Self>, PrimitivesError> {
-        let mut hasher = Sha256::new();
-        hasher.update([cs_id.as_ref(), data.as_ref()].concat());
-        let mut seed = [0u8; 32];
-        seed.copy_from_slice(hasher.finalize().as_ref());
-        let mut rng = ChaCha20Rng::from_seed(seed);
-        loop {
-            let x = Self::BaseField::rand(&mut rng);
-            // a boolean flag to decide if y is positive or not
-            let y_flag = rng.gen();
-            if let Some(p) = GroupAffine::<Self>::get_point_from_x(x, y_flag) {
-                return Ok(p.mul_by_cofactor_to_projective());
-            }
-        }
-    }
-}
-
-impl HashToGroup for ark_bls12_381::g1::Parameters {
-    // TODO:
-    // overload hash to group with the method in
-    // <https://github.com/algorand/pairing-plus/blob/7ec2ae03aae4ba2fc5210810211478171ccededf/src/bls12_381/osswu_map/g1.rs#L47>
-}
-
-impl HashToGroup for ark_bls12_377::g1::Parameters {
-    // TODO:
-    // overload hash to group with the method in
-    // <https://github.com/algorand/pairing-plus/blob/7ec2ae03aae4ba2fc5210810211478171ccededf/src/bls12_381/osswu_map/g1.rs#L47>
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-    use ark_std::vec;
-
-    #[test]
-    fn test_hash_to_group() {
-        test_hash_to_group_helper::<ark_bls12_381::g1::Parameters>();
-        test_hash_to_group_helper::<ark_bls12_377::g1::Parameters>();
-    }
-
-    fn test_hash_to_group_helper<P: HashToGroup>() {
-        let data = vec![1u8, 2, 3, 4, 5];
-        let _g1 =
-            <P as HashToGroup>::hash_to_group::<&[u8]>(data.as_ref(), "bls signature".as_ref())
-                .unwrap();
-    }
-}
+pub use short_weierstrass::SWHashToGroup;
+pub use twisted_edwards::TEHashToGroup;

primitives/src/hash_to_group/short_weierstrass.rs

@@ -0,0 +1,81 @@
+// Copyright (c) 2022 Espresso Systems (espressosys.com)
+// This file is part of the Jellyfish library.
+
+// You should have received a copy of the MIT License
+// along with the Jellyfish library. If not, see <https://mit-license.org/>.
+
+//! Hash to Elliptic Curve implementation of <https://datatracker.ietf.org/doc/draft-irtf-cfrg-hash-to-curve/>
+
+use crate::errors::PrimitivesError;
+use ark_ec::{
+    short_weierstrass_jacobian::{GroupAffine, GroupProjective},
+    AffineCurve, SWModelParameters,
+};
+use ark_std::{
+    rand::{Rng, SeedableRng},
+    UniformRand,
+};
+use digest::Digest;
+use rand_chacha::ChaCha20Rng;
+use sha2::Sha256;
+
+/// Trait definition and default implementation for hash to group functions for
+/// Short Weierstrass Curves.
+pub trait SWHashToGroup: SWModelParameters + Sized {
+    /// Hash to Group point, using sha2-512 function
+    /// hashing to G1 point of `C: ProjectiveCurve`.
+    // Default implementation implements a naive solution via rejection sampling.
+    // Slow, and non-constant time.
+    //
+    // For specific curves we may want to overload it with a more efficient
+    // algorithm, such as IETF BLS draft.
+    fn hash_to_group<B: AsRef<[u8]>>(
+        data: B,
+        cs_id: B,
+    ) -> Result<GroupProjective<Self>, PrimitivesError> {
+        let mut hasher = Sha256::new();
+        hasher.update([cs_id.as_ref(), data.as_ref()].concat());
+        let mut seed = [0u8; 32];
+        seed.copy_from_slice(hasher.finalize().as_ref());
+        let mut rng = ChaCha20Rng::from_seed(seed);
+        loop {
+            let x = Self::BaseField::rand(&mut rng);
+            // a boolean flag to decide if y is positive or not
+            let y_flag = rng.gen();
+            if let Some(p) = GroupAffine::<Self>::get_point_from_x(x, y_flag) {
+                return Ok(p.mul_by_cofactor_to_projective());
+            }
+        }
+    }
+}
+
+impl SWHashToGroup for ark_bls12_381::g1::Parameters {
+    // TODO:
+    // overload hash to group with the method in
+    // <https://github.com/algorand/pairing-plus/blob/7ec2ae03aae4ba2fc5210810211478171ccededf/src/bls12_381/osswu_map/g1.rs#L47>
+}
+
+impl SWHashToGroup for ark_bls12_377::g1::Parameters {
+    // TODO:
+    // overload hash to group with the method in
+    // <https://github.com/algorand/pairing-plus/blob/7ec2ae03aae4ba2fc5210810211478171ccededf/src/bls12_381/osswu_map/g1.rs#L47>
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use ark_std::vec;
+
+    #[test]
+    fn test_hash_to_group() {
+        test_hash_to_group_helper::<ark_bls12_381::g1::Parameters>();
+        test_hash_to_group_helper::<ark_bls12_377::g1::Parameters>();
+    }
+
+    fn test_hash_to_group_helper<P: SWHashToGroup>() {
+        let data = vec![1u8, 2, 3, 4, 5];
+        let _g1 =
+            <P as SWHashToGroup>::hash_to_group::<&[u8]>(data.as_ref(), "bls signature".as_ref())
+                .unwrap();
+    }
+}

primitives/src/hash_to_group/twisted_edwards.rs

@@ -0,0 +1,81 @@
+// Copyright (c) 2022 Espresso Systems (espressosys.com)
+// This file is part of the Jellyfish library.
+
+// You should have received a copy of the MIT License
+// along with the Jellyfish library. If not, see <https://mit-license.org/>.
+
+//! Hash to Elliptic Curve implementation of <https://datatracker.ietf.org/doc/draft-irtf-cfrg-hash-to-curve/>
+
+use crate::errors::PrimitivesError;
+use ark_ec::{
+    twisted_edwards_extended::{GroupAffine, GroupProjective},
+    AffineCurve, TEModelParameters,
+};
+use ark_std::{
+    rand::{Rng, SeedableRng},
+    UniformRand,
+};
+use digest::Digest;
+use rand_chacha::ChaCha20Rng;
+use sha2::Sha256;
+
+/// Trait definition and default implementation for hash to group functions for
+/// Twisted Edwards Curves.
+pub trait TEHashToGroup: TEModelParameters + Sized {
+    /// Hash to Group point, using sha2-512 function
+    /// hashing to G1 point of `C: ProjectiveCurve`.
+    // Default implementation implements a naive solution via rejection sampling.
+    // Slow, and non-constant time.
+    //
+    // For specific curves we may want to overload it with a more efficient
+    // algorithm, such as IETF BLS draft.
+    fn hash_to_group<B: AsRef<[u8]>>(
+        data: B,
+        cs_id: B,
+    ) -> Result<GroupProjective<Self>, PrimitivesError> {
+        let mut hasher = Sha256::new();
+        hasher.update([cs_id.as_ref(), data.as_ref()].concat());
+        let mut seed = [0u8; 32];
+        seed.copy_from_slice(hasher.finalize().as_ref());
+        let mut rng = ChaCha20Rng::from_seed(seed);
+        loop {
+            let x = Self::BaseField::rand(&mut rng);
+            // a boolean flag to decide if y is positive or not
+            let y_flag = rng.gen();
+            if let Some(p) = GroupAffine::<Self>::get_point_from_x(x, y_flag) {
+                return Ok(p.mul_by_cofactor_to_projective());
+            }
+        }
+    }
+}
+
+impl TEHashToGroup for ark_ed_on_bls12_377::EdwardsParameters {
+    // TODO:
+    // overload hash to group with the method in
+    // <https://github.com/algorand/pairing-plus/blob/7ec2ae03aae4ba2fc5210810211478171ccededf/src/bls12_381/osswu_map/g1.rs#L47>
+}
+
+impl TEHashToGroup for ark_ed_on_bls12_381::EdwardsParameters {
+    // TODO:
+    // overload hash to group with the method in
+    // <https://github.com/algorand/pairing-plus/blob/7ec2ae03aae4ba2fc5210810211478171ccededf/src/bls12_381/osswu_map/g1.rs#L47>
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use ark_std::vec;
+
+    #[test]
+    fn test_hash_to_group() {
+        test_hash_to_group_helper::<ark_ed_on_bls12_377::EdwardsParameters>();
+        test_hash_to_group_helper::<ark_ed_on_bls12_381::EdwardsParameters>();
+    }
+
+    fn test_hash_to_group_helper<P: TEHashToGroup>() {
+        let data = vec![1u8, 2, 3, 4, 5];
+        let _g1 =
+            <P as TEHashToGroup>::hash_to_group::<&[u8]>(data.as_ref(), "Jubjub curves".as_ref())
+                .unwrap();
+    }
+}

primitives/src/signatures/bls.rs

@@ -1,7 +1,9 @@
 //! Placeholder for BLS signature.
 
 use super::SignatureScheme;
-use crate::{constants::CS_ID_BLS_SIG_NAIVE, errors::PrimitivesError, hash_to_group::HashToGroup};
+use crate::{
+    constants::CS_ID_BLS_SIG_NAIVE, errors::PrimitivesError, hash_to_group::SWHashToGroup,
+};
 use ark_ec::{
     bls12::{Bls12, Bls12Parameters},
     short_weierstrass_jacobian::GroupAffine,
@@ -51,7 +53,7 @@ pub struct BLSSignature<P: Bls12Parameters>(pub(crate) GroupAffine<P::G1Paramete
 impl<P> SignatureScheme for BLSSignatureScheme<P>
 where
     P: Bls12Parameters,
-    P::G1Parameters: HashToGroup,
+    P::G1Parameters: SWHashToGroup,
 {
     const CS_ID: &'static str = CS_ID_BLS_SIG_NAIVE;
 
@@ -105,7 +107,7 @@ where
         msg: M,
         _prng: &mut R,
     ) -> Result<Self::Signature, PrimitivesError> {
-        let hm = <P::G1Parameters as HashToGroup>::hash_to_group(
+        let hm = <P::G1Parameters as SWHashToGroup>::hash_to_group(
             msg.as_ref(),
             CS_ID_BLS_SIG_NAIVE.as_ref(),
         )?;
@@ -119,7 +121,7 @@ where
         msg: M,
         sig: &Self::Signature,
     ) -> Result<(), PrimitivesError> {
-        let hm = <P::G1Parameters as HashToGroup>::hash_to_group(
+        let hm = <P::G1Parameters as SWHashToGroup>::hash_to_group(
             msg.as_ref(),
             CS_ID_BLS_SIG_NAIVE.as_ref(),
         )?;

primitives/src/vrf/blsvrf.rs

@@ -4,7 +4,7 @@ use super::Vrf;
 use crate::{
     constants::CS_ID_BLS_VRF_NAIVE,
     errors::PrimitivesError,
-    hash_to_group::HashToGroup,
+    hash_to_group::SWHashToGroup,
     signatures::{
         bls::{BLSSignKey, BLSSignature, BLSVerKey},
         BLSSignatureScheme, SignatureScheme,
@@ -29,7 +29,7 @@ impl<H, P> Vrf<H, P> for BLSVRFScheme<P>
 where
     H: Digest,
     P: Bls12Parameters,
-    P::G1Parameters: HashToGroup,
+    P::G1Parameters: SWHashToGroup,
 {
     const CS_ID: &'static str = CS_ID_BLS_VRF_NAIVE;