privacy-scaling-explorations · kilic · May 24, 2024 · Mar 26, 2024 · Apr 5, 2024 · Apr 5, 2024
diff --git a/Cargo.toml b/Cargo.toml
@@ -43,6 +43,9 @@ hex = { version = "0.4", optional = true, default-features = false, features = [
 blake2b_simd = "1"
 rayon = "1.8"
 unroll = "0.1.5"
+blake2 = "0.10.6"
+sha2 = "0.10.8"
+digest = "0.10.7"
 
 [features]
 default = ["bits"]

diff --git a/src/bn256/curve.rs b/src/bn256/curve.rs
@@ -11,7 +11,6 @@ use crate::ff::WithSmallOrderMulGroup;
 use crate::ff::{Field, PrimeField};
 use crate::group::Curve;
 use crate::group::{cofactor::CofactorGroup, prime::PrimeCurveAffine, Group, GroupEncoding};
-use crate::hash_to_curve::svdw_hash_to_curve;
 use crate::{
     impl_add_binop_specify_output, impl_binops_additive, impl_binops_additive_specify_output,
     impl_binops_multiplicative, impl_binops_multiplicative_mixed, impl_sub_binop_specify_output,
@@ -39,7 +38,7 @@ new_curve_impl!(
     G1_A,
     G1_B,
     "bn256_g1",
-    |curve_id, domain_prefix| svdw_hash_to_curve(curve_id, domain_prefix, G1::SVDW_Z),
+    |domain_prefix| crate::hash_to_curve::hash_to_curve(domain_prefix, G1::default_hash_to_curve_suite()),
 );
 
 new_curve_impl!(
@@ -52,9 +51,18 @@ new_curve_impl!(
     G2_A,
     G2_B,
     "bn256_g2",
-    |_, _| unimplemented!(),
+    |domain_prefix| hash_to_curve_g2(domain_prefix),
 );
 
+#[allow(clippy::type_complexity)]
+pub(crate) fn hash_to_curve_g2<'a>(domain_prefix: &'a str) -> Box<dyn Fn(&[u8]) -> G2 + 'a> {
+    let suite = G2::default_hash_to_curve_suite();
+    Box::new(move |message| {
+        let r0 = suite.hash_to_curve(domain_prefix, message);
+        r0.clear_cofactor()
+    })
+}
+
 const G1_GENERATOR_X: Fq = Fq::one();
 const G1_GENERATOR_Y: Fq = Fq::from_raw([2, 0, 0, 0]);
 const G1_A: Fq = Fq::from_raw([0, 0, 0, 0]);
@@ -195,6 +203,26 @@ impl CofactorGroup for G2 {
 
 impl G1 {
     const SVDW_Z: Fq = Fq::ONE;
+
+    fn default_hash_to_curve_suite() -> crate::hash_to_curve::Suite<Self, sha2::Sha256, 64> {
+        crate::hash_to_curve::Suite::<G1, sha2::Sha256, 64>::new(
+            b"bn256_g1_XMD:SHA-256_SVDW_RO_",
+            Self::SVDW_Z,
+            crate::hash_to_curve::Method::SVDW,
+        )
+    }
+}
+
+impl G2 {
+    const SVDW_Z: Fq2 = Fq2::ONE;
+
+    fn default_hash_to_curve_suite() -> crate::hash_to_curve::Suite<Self, sha2::Sha256, 128> {
+        crate::hash_to_curve::Suite::<G2, sha2::Sha256, 128>::new(
+            b"bn256_g2_XMD:SHA-256_SVDW_RO_",
+            Self::SVDW_Z,
+            crate::hash_to_curve::Method::SVDW,
+        )
+    }
 }
 
 #[cfg(test)]

diff --git a/src/bn256/fq.rs b/src/bn256/fq.rs
@@ -294,70 +294,5 @@ mod test {
     crate::field_testing_suite!(Fq, "constants", MODULUS_STR);
     crate::field_testing_suite!(Fq, "sqrt");
     crate::field_testing_suite!(Fq, "zeta");
-    crate::field_testing_suite!(
-        Fq,
-        "from_uniform_bytes",
-        [
-            Fq::from_raw([
-                0xd1f334151139642a,
-                0xb0f28bcaa90fdb88,
-                0x9a13255d88eca613,
-                0x02afef300dd32d9a,
-            ]),
-            Fq::from_raw([
-                0x03cd906680808fbe,
-                0xc28902db5aef5254,
-                0x3dbdb406ae292ddf,
-                0x276ec249e6b9e195
-            ]),
-            Fq::from_raw([
-                0xb0e07ded189e91f7,
-                0x9e3b0caae2b98899,
-                0x49e511f19341fdcf,
-                0x1ea71260f64b72da
-            ]),
-            Fq::from_raw([
-                0x61132be14bb978d4,
-                0xe27e09a20808067b,
-                0x3842cc8fd1d8406f,
-                0x13163c8a13fd550b
-            ]),
-            Fq::from_raw([
-                0x04a6495a33d39ac5,
-                0xc918e75bb383fae0,
-                0x80068784d577b035,
-                0x1dd962b86e44e1be
-            ]),
-            Fq::from_raw([
-                0x107ffeecf4cb3348,
-                0x53a0adb5491a4944,
-                0x50028f636ffcb780,
-                0x0af7f3aa38015c1d
-            ]),
-            Fq::from_raw([
-                0x22513787342eba07,
-                0x4fac22ed88770319,
-                0x0b7c31082cc92b13,
-                0x250e22a8cac6e790
-            ]),
-            Fq::from_raw([
-                0x5954fd7dda014940,
-                0x9df859b2124e66fa,
-                0xaab48d94eadd9d14,
-                0x2a9a75013e3da632
-            ]),
-            Fq::from_raw([
-                0xedd59c88fee718de,
-                0x2b034dcfe6de3844,
-                0x76b0e2e360488694,
-                0x068998ef20d62df1
-            ]),
-            Fq::from_raw([
-                0xac161667911634a4,
-                0x296c2f453152552f,
-                0x2653625dfaa1cf74,
-                0x171abf201a2587d7
-            ]),
-        ]
-    );
+    crate::field_testing_suite!(Fq, "from_uniform_bytes", 64);
 }
diff --git a/src/bn256/fq2.rs b/src/bn256/fq2.rs
@@ -472,6 +472,15 @@ impl FromUniformBytes<64> for Fq2 {
         Self::new(Fq::from_uniform_bytes(bytes), Fq::zero())
     }
 }
+
+impl FromUniformBytes<128> for Fq2 {
+    fn from_uniform_bytes(bytes: &[u8; 128]) -> Self {
+        let c0 = bytes[..64].try_into().unwrap();
+        let c1 = bytes[64..].try_into().unwrap();
+        Self::new(Fq::from_uniform_bytes(c0), Fq::from_uniform_bytes(c1))
+    }
+}
+
 #[derive(Clone, Copy, Debug)]
 pub struct Fq2Bytes([u8; 64]);
 

diff --git a/src/bn256/fr.rs b/src/bn256/fr.rs
@@ -332,6 +332,7 @@ impl WithSmallOrderMulGroup<3> for Fr {
 
 #[cfg(test)]
 mod test {
+
     use super::*;
     crate::field_testing_suite!(Fr, "field_arithmetic");
     crate::field_testing_suite!(Fr, "conversion");
@@ -342,72 +343,7 @@ mod test {
     crate::field_testing_suite!(Fr, "constants", MODULUS_STR);
     crate::field_testing_suite!(Fr, "sqrt");
     crate::field_testing_suite!(Fr, "zeta");
-    crate::field_testing_suite!(
-        Fr,
-        "from_uniform_bytes",
-        [
-            Fr::from_raw([
-                0x2ca6366467811a07,
-                0x22727e3db430ed7e,
-                0xbdb79bcb97d9e250,
-                0x2cee6d1152d1d7b0
-            ]),
-            Fr::from_raw([
-                0x6ec33f1a3af8cb2d,
-                0x2c8f3330e85dab4b,
-                0xfeeff4ae1b019172,
-                0x095cd2a455dd67b6
-            ]),
-            Fr::from_raw([
-                0x4741eee9c02c9f33,
-                0xfc0111dd8aeb7e7a,
-                0xb1d79e2a22d4ab08,
-                0x0cb7168893a7bbda
-            ]),
-            Fr::from_raw([
-                0xc2ff8410555287f8,
-                0x0927fbea8c6049c8,
-                0xc0edccc8e4d3efe4,
-                0x1d724b76911436c4
-            ]),
-            Fr::from_raw([
-                0xdef98bc8d4db6e5b,
-                0x42f0ea50590d557e,
-                0x1f311a3b8114fd9a,
-                0x0487c555645c67b1
-            ]),
-            Fr::from_raw([
-                0x8ad4879b05ceb610,
-                0x2e4e9a46537c84b0,
-                0x5cfa7c43c9dfcfa1,
-                0x0b6b2a4d122d0bb6
-            ]),
-            Fr::from_raw([
-                0xe7f11ee016df7fe7,
-                0x6419da89bd8aef3d,
-                0x3511f5d293af95c8,
-                0x10379c1d4d49593a
-            ]),
-            Fr::from_raw([
-                0xd63080c8aa3ecd37,
-                0x19c20f30b56fe458,
-                0xc9dbbcb3aa780e06,
-                0x28a4e2b8273762c6
-            ]),
-            Fr::from_raw([
-                0xecea51b521eac0b8,
-                0x65fff58a5881c562,
-                0x603ac7d1e06ef3af,
-                0x1e0c2c51226eecea
-            ]),
-            Fr::from_raw([
-                0xe6ec4779b8bd6516,
-                0x0d5411f3cb9504ae,
-                0xff706ec73df8e92a,
-                0x2c56d60b3e351e56
-            ]),
-        ]
-    );
+    crate::field_testing_suite!(Fr, "from_uniform_bytes", 64);
 
     #[test]
     fn bench_fr_from_u16() {

diff --git a/src/bn256/mod.rs b/src/bn256/mod.rs
@@ -16,53 +16,3 @@ pub use fq12::*;
 pub use fq2::*;
 pub use fq6::*;
 pub use fr::*;
-
-#[cfg(test)]
-mod test {
-    use super::G1 as Bn256Point;
-    use group::GroupEncoding;
-    use pasta_curves::arithmetic::CurveExt;
-    use rand_core::{RngCore, SeedableRng};
-
-    #[test]
-    fn test_consistent_hash_to_curve() {
-        // The goal of this test is to generate test vectors to ensure that the ASM implementation
-        // matches the rust implementation.
-        let num_vecs = 10;
-
-        // Test vectors generated with rust implementation.
-        let expected_results = [
-            "e0c5a6834e0329b4f8bdc91144b3e687ac9d810a8e899415267db9cfbf61e91e",
-            "7052a20bee99cbe054fdd8b2e336db3ed3e9a265229e44ab8197c5eabdef2b0b",
-            "2f058acc133957074ac79e9b9b1867a0cf3d13df7aa7de7f48e9a6be7d96aaad",
-            "b2ff44a25693b811f35e33feb3e99ad9ba0d06425a3ffd5e79cef63d20143314",
-            "ab2f6d71d2fde51546d8a5782aa9f707e585b84644470f0c876784dbebd30c95",
-            "6a4e0e30f37a8d1b92b8cf08df3735a36b4937ee455a9dc5f9283a13530db184",
-            "f1c69be8c5f5f9e28b0e9f76ab77651a7dcaaae371fbba66450cbcee0ed5b1ab",
-            "e86267c2e3355d7a6f664a0ea71374406337d452a3f9a294a0594df53c08df21",
-            "03cf55ca983ecd8a2e2baae18d979d97d688a978d829701c66a14d7c4da58ea2",
-            "5302c2cfe3c909e9378d08c951bb33d0813818a1baf734379aac8aaa47f38f0d",
-        ];
-
-        let mut seeded_rng = rand_chacha::ChaChaRng::seed_from_u64(0u64);
-        let uniform_bytes = std::iter::from_fn(|| {
-            let mut bytes = [0u8; 32];
-            seeded_rng.fill_bytes(&mut bytes);
-            Some(bytes)
-        })
-        .take(num_vecs)
-        .collect::<Vec<_>>();
-        let hash = Bn256Point::hash_to_curve("from_uniform_bytes");
-        for i in 0..num_vecs {
-            let p = hash(&uniform_bytes[i]);
-            let expected_result = hex::decode(expected_results[i]).unwrap();
-            assert_eq!(
-                p.to_bytes().as_ref(),
-                &expected_result[..],
-                "hash_to_curve_print failed, expected: {}, got: {}",
-                expected_results[i],
-                hex::encode(p.to_bytes().as_ref())
-            );
-        }
-    }
-}
diff --git a/src/derive/curve.rs b/src/derive/curve.rs
@@ -724,7 +724,7 @@ macro_rules! new_curve_impl {
 
             #[allow(clippy::redundant_closure_call)]
             fn hash_to_curve<'a>(domain_prefix: &'a str) -> Box<dyn Fn(&[u8]) -> Self + 'a> {
-                $hash_to_curve($curve_id, domain_prefix)
+                $hash_to_curve(domain_prefix)
             }
 
             fn is_on_curve(&self) -> Choice {