refactor: pass public key commitment [skip-line-limit]

crates/aggregator/Cargo.toml

@@ -18,6 +18,7 @@ e3-evm = { workspace = true }
 e3-fhe = { workspace = true }
 e3-multithread = { workspace = true }
 e3-trbfv = { workspace = true }
+e3-bfv-helpers = { workspace = true }
 e3-request = { workspace = true }
 e3-sortition = {  workspace = true }
 e3-utils = { workspace = true }

crates/aggregator/src/publickey_aggregator.rs

@@ -6,6 +6,7 @@
 
 use actix::prelude::*;
 use anyhow::Result;
+use e3_bfv_helpers::client::compute_pk_commitment;
 use e3_data::Persistable;
 use e3_events::{
     prelude::*, BusHandle, Die, E3id, EnclaveEvent, EnclaveEventData, KeyshareCreated, OrderedSet,
@@ -181,6 +182,13 @@ impl Handler<ComputeAggregate> for PublicKeyAggregator {
             keyshares: msg.keyshares,
         })?;
 
+        let public_key_hash = compute_pk_commitment(
+            pubkey.clone(),
+            self.fhe.params.degree(),
+            self.fhe.params.plaintext(),
+            self.fhe.params.moduli().to_vec(),
+        )?;
+
         // Update the local state
         self.set_pubkey(pubkey)?;
 
@@ -194,6 +202,7 @@ impl Handler<ComputeAggregate> for PublicKeyAggregator {
             info!("Sending PublicKeyAggregated...");
             let event = PublicKeyAggregated {
                 pubkey,
+                public_key_hash,
                 e3_id: msg.e3_id,
                 nodes,
             };

crates/bfv-helpers/src/client.rs

@@ -5,6 +5,7 @@
 // or FITNESS FOR A PARTICULAR PURPOSE.
 
 use crate::build_bfv_params_arc;
+use crate::utils::greco::bfv_public_key_to_greco;
 use anyhow::{anyhow, Result};
 use fhe::bfv::{Encoding, Plaintext, PublicKey};
 use fhe::Error as FheError;
@@ -129,6 +130,46 @@ where
     })
 }
 
+pub fn compute_pk_commitment(
+    public_key: Vec<u8>,
+    degree: usize,
+    plaintext_modulus: u64,
+    moduli: Vec<u64>,
+) -> Result<[u8; 32]> {
+    use shared::commitments::compute_pk_commitment as _compute_pk_commitment;
+    use shared::template::calculate_bit_width;
+
+    let params = build_bfv_params_arc(degree, plaintext_modulus, &moduli, None);
+
+    let public_key = PublicKey::from_bytes(&public_key, &params)
+        .map_err(|e| anyhow!("Error deserializing public key: {}", e))?;
+
+    let (_, bounds) = GrecoBounds::compute(&params, 0)?;
+    let bit_pk = calculate_bit_width(&bounds.pk_bounds[0].to_string())?;
+
+    let (pk0is, pk1is) = bfv_public_key_to_greco(&public_key, &params);
+    let commitment_bigint = _compute_pk_commitment(&pk0is, &pk1is, bit_pk);
+
+    let bytes = commitment_bigint.to_bytes_be().1;
+
+    if bytes.len() > 32 {
+        return Err(anyhow!(
+            "Commitment must be at most 32 bytes, got {}",
+            bytes.len()
+        ));
+    }
+
+    let mut padded_bytes = vec![0u8; 32];
+    let start_idx = 32 - bytes.len();
+    padded_bytes[start_idx..].copy_from_slice(&bytes);
+
+    let public_key_hash: [u8; 32] = padded_bytes
+        .try_into()
+        .map_err(|_| anyhow!("Failed to convert padded bytes to array"))?;
+
+    Ok(public_key_hash)
+}
+
 #[cfg(test)]
 mod tests {
     use crate::BfvParamSets;