draft version of pub key aggregation

src/key.rs

@@ -4,6 +4,9 @@ use ff::{PrimeField, PrimeFieldBits};
 use group::Curve;
 use rand_core::{CryptoRng, RngCore};
 
+#[cfg(feature = "multicore")]
+use rayon::prelude::*;
+
 #[cfg(feature = "pairing")]
 use bls12_381::{hash_to_curve::HashToField, G1Affine, G1Projective, Scalar};
 #[cfg(feature = "pairing")]
@@ -359,3 +362,21 @@ mod tests {
         assert!(PublicKey::from_bytes(&[255u8; 48]).is_err());
     }
 }
+
+pub fn aggregate_public_keys(public_keys: &[PublicKey]) -> Result<PublicKey, Error> {
+
+    if public_keys.is_empty() {
+        return Err(Error::ZeroSizedInput);
+    }
+
+    let res = public_keys
+        .into_par_iter()
+        .fold(G1Projective::identity, |mut acc, public_key| {
+            acc += &public_key.0;
+            acc
+        })
+        .reduce(G1Projective::identity, |acc, val| acc + val);
+
+    Ok(PublicKey(res.into()))
+}
+

src/lib.rs

@@ -7,7 +7,7 @@ mod signature;
 
 pub use self::error::Error;
 pub use self::key::{PrivateKey, PublicKey, Serialize};
-pub use self::signature::{aggregate, hash, verify, verify_messages, Signature};
+pub use self::signature::{aggregate, hash, verify, verify_messages, verify_agg_signatures_on_same_hash, Signature};
 
 #[cfg(test)]
 #[macro_use]

src/signature.rs

@@ -179,6 +179,14 @@ pub fn verify(signature: &Signature, hashes: &[G2Projective], public_keys: &[Pub
     ml.final_exponentiation() == Gt::identity()
 }
 
+pub fn verify_agg_signatures_on_same_hash(signature: &Signature, hash: &G2Projective, public_keys: &[PublicKey]) -> bool {
+    // Aggregate the public keys into a single public key
+    let pub_key_aggregated = aggregate_public_keys(public_keys).unwrap();
+
+    // Verify this as normal
+    verify(signature, std::slice::from_ref(hash), std::slice::from_ref(&pub_key_aggregated))
+}
+
 /// Verifies that the signature is the actual aggregated signature of messages - pubkeys.
 /// Calculated by `e(g1, signature) == \prod_{i = 0}^n e(pk_i, hash_i)`.
 #[cfg(feature = "pairing")]