From 386c56ceeab78a412f47ec1f8ad3e736dfee3f8f Mon Sep 17 00:00:00 2001
From: Timofey Luin <timofey.luin@gmail.com>
Date: Tue, 27 Feb 2024 14:55:50 +0100
Subject: [PATCH 1/2] aggregate from pk[0] or identity

---
 lightclient-circuits/src/sync_step_circuit.rs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lightclient-circuits/src/sync_step_circuit.rs b/lightclient-circuits/src/sync_step_circuit.rs
index 0045719..95e52e8 100644
--- a/lightclient-circuits/src/sync_step_circuit.rs
+++ b/lightclient-circuits/src/sync_step_circuit.rs
@@ -375,20 +375,24 @@ impl<S: Spec, F: Field> StepCircuit<S, F> {
             participation_bits.push(participation_bit);
         }
 
-        let rand_point = g1_chip.load_random_point::<G1Affine>(ctx);
-        let mut acc = rand_point.clone();
+        let mut acc = {
+            let x = fp_chip.load_constant(ctx, G1Affine::identity().x);
+            let y = fp_chip.load_constant(ctx, G1Affine::identity().y);
+            G1Point::new(x, y) // identity
+        };
+        acc = g1_chip.select(ctx, assigned_affines[0].clone(), acc, participation_bits[0]);
         for (bit, point) in participation_bits
             .iter()
             .copied()
             .zip(assigned_affines.iter_mut())
+            .skip(1)
         {
             let sum = g1_chip.add_unequal(ctx, acc.clone(), point.clone(), true);
             acc = g1_chip.select(ctx, sum, acc, bit);
         }
-        let agg_pubkey = g1_chip.sub_unequal(ctx, acc, rand_point, false);
         let participation_sum = gate.sum(ctx, participation_bits);
 
-        (agg_pubkey, participation_sum)
+        (acc, participation_sum)
     }
 }
 

From 2fc84efa93c461aa1d3379af5dd5c638fc17badc Mon Sep 17 00:00:00 2001
From: Timofey Luin <timofey.luin@gmail.com>
Date: Tue, 5 Mar 2024 14:18:40 +0100
Subject: [PATCH 2/2] fix merge

---
 lightclient-circuits/src/sync_step_circuit.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lightclient-circuits/src/sync_step_circuit.rs b/lightclient-circuits/src/sync_step_circuit.rs
index 543a765..175f791 100644
--- a/lightclient-circuits/src/sync_step_circuit.rs
+++ b/lightclient-circuits/src/sync_step_circuit.rs
@@ -319,7 +319,7 @@ impl<S: Spec, F: Field> StepCircuit<S, F> {
         fp_chip: &FpChip<'_, F>,
         pubkey_affines: &[G1Affine],
         pariticipation_bits: &[bool],
-        assigned_pubkeys: &mut Vec<G1Point<F>>,
+        assigned_affines: &mut Vec<G1Point<F>>,
         y_signs_packed: &mut Vec<AssignedValue<F>>,
     ) -> (G1Point<F>, AssignedValue<F>) {
         let gate = fp_chip.gate();
@@ -355,7 +355,7 @@ impl<S: Spec, F: Field> StepCircuit<S, F> {
                 fp_chip.limb_bases[1],
             );
 
-            assigned_pubkeys.push(assigned_affine);
+            assigned_affines.push(assigned_affine);
             participation_bits.push(participation_bit);
             y_signs.push(y_sign);
         }
@@ -380,6 +380,11 @@ impl<S: Spec, F: Field> StepCircuit<S, F> {
         }
         let participation_sum = gate.sum(ctx, participation_bits);
 
+        *y_signs_packed = y_signs
+            .chunks(F::CAPACITY as usize - 1)
+            .map(|chunk| gate.bits_to_num(ctx, chunk))
+            .collect_vec();
+
         (acc, participation_sum)
     }
 }