Fix step circuit default witness

lightclient-circuits/Cargo.toml

@@ -45,6 +45,7 @@ strum_macros = "0.25"
 rand = "0.8"
 lazy_static = "1.4"
 getset = "0.1.2"
+rand_chacha = "0.3.0"
 
 [dev-dependencies]
 rstest = "0.18.2"

lightclient-circuits/config/sync_step_20.json

@@ -2,7 +2,7 @@
   "params": {
     "k": 20,
     "num_advice_per_phase": [
-      12
+      15
     ],
     "num_fixed": 1,
     "num_lookup_advice_per_phase": [
@@ -15,16 +15,19 @@
   },
   "break_points": [
     [
-      1048566,
-      1048564,
-      1048566,
       1048566,
       1048565,
+      1048565,
       1048566,
+      1048564,
       1048566,
-      1048566,
+      1048565,
       1048564,
       1048566,
+      1048565,
+      1048564,
+      1048564,
+      1048564,
       1048566
     ]
   ]

lightclient-circuits/config/sync_step_testnet.json

@@ -2,7 +2,7 @@
   "params": {
     "k": 21,
     "num_advice_per_phase": [
-      7
+      8
     ],
     "num_fixed": 1,
     "num_lookup_advice_per_phase": [
@@ -15,12 +15,13 @@
   },
   "break_points": [
     [
-      2097141,
-      2097141,
       2097142,
       2097140,
+      2097140,
       2097142,
-      2097141
+      2097141,
+      2097140,
+      2097142
     ]
   ]
 }

lightclient-circuits/src/sync_step_circuit.rs

@@ -274,32 +274,7 @@ impl<S: Spec, F: Field> StepCircuit<S, F> {
             poseidon_commitment,
         ]]
     }
-}
-
-// Truncate the SHA256 digest to 253 bits and convert to one field element.
-pub fn truncate_sha256_into_single_elem<F: Field>(
-    ctx: &mut Context<F>,
-    gate: &impl GateInstructions<F>,
-    hash_bytes: [AssignedValue<F>; 32],
-) -> AssignedValue<F> {
-    let public_input_commitment_bytes = {
-        let mut truncated_hash = hash_bytes;
-        let cleared_byte = {
-            let bits = gate.num_to_bits(ctx, truncated_hash[31], 8);
-            gate.bits_to_num(ctx, &bits[..5])
-        };
-        truncated_hash[31] = cleared_byte;
-        truncated_hash
-    };
-
-    let byte_bases = (0..32)
-        .map(|i| QuantumCell::Constant(gate.pow_of_two()[i * 8]))
-        .collect_vec();
-
-    gate.inner_product(ctx, public_input_commitment_bytes, byte_bases)
-}
 
-impl<S: Spec, F: Field> StepCircuit<S, F> {
     /// Decompresses siganure from bytes and assigns it to the circuit.
     fn assign_signature(
         ctx: &mut Context<F>,
@@ -389,6 +364,29 @@ impl<S: Spec, F: Field> StepCircuit<S, F> {
     }
 }
 
+// Truncate the SHA256 digest to 253 bits and convert to one field element.
+pub fn truncate_sha256_into_single_elem<F: Field>(
+    ctx: &mut Context<F>,
+    gate: &impl GateInstructions<F>,
+    hash_bytes: [AssignedValue<F>; 32],
+) -> AssignedValue<F> {
+    let public_input_commitment_bytes = {
+        let mut truncated_hash = hash_bytes;
+        let cleared_byte = {
+            let bits = gate.num_to_bits(ctx, truncated_hash[31], 8);
+            gate.bits_to_num(ctx, &bits[..5])
+        };
+        truncated_hash[31] = cleared_byte;
+        truncated_hash
+    };
+
+    let byte_bases = (0..32)
+        .map(|i| QuantumCell::Constant(gate.pow_of_two()[i * 8]))
+        .collect_vec();
+
+    gate.inner_product(ctx, public_input_commitment_bytes, byte_bases)
+}
+
 impl<S: Spec> AppCircuit for StepCircuit<S, bn256::Fr> {
     type Pinning = Eth2ConfigPinning;
     type Witness = witness::SyncStepArgs<S>;

lightclient-circuits/src/witness/step.rs

@@ -5,13 +5,14 @@
 use eth_types::Spec;
 use ethereum_consensus_types::signing::compute_signing_root;
 use ethereum_consensus_types::BeaconBlockHeader;
+use ff::Field;
 use halo2curves::bls12_381::hash_to_curve::ExpandMsgXmd;
 use halo2curves::bls12_381::{hash_to_curve, Fr, G1, G2};
 use halo2curves::group::Curve;
 use itertools::Itertools;
+use rand::SeedableRng;
 use serde::{Deserialize, Serialize};
 use ssz_rs::{Merkleized, Node};
-use std::iter;
 use std::marker::PhantomData;
 use std::ops::Deref;
 
@@ -86,30 +87,38 @@ impl<S: Spec> Default for SyncStepArgs<S> {
         let signing_root =
             compute_signing_root(attested_header.hash_tree_root().unwrap(), DOMAIN).unwrap();
 
-        let sk = Fr::from_bytes(&[1; 32]).unwrap();
+        let mut rng = rand_chacha::ChaCha8Rng::seed_from_u64(0);
+
+        let sks = (0..S::SYNC_COMMITTEE_SIZE)
+            .map(|_| Fr::random(&mut rng))
+            .collect_vec();
         let msg = <G2 as hash_to_curve::HashToCurve<ExpandMsgXmd<sha2::Sha256>>>::hash_to_curve(
             signing_root.deref(),
             S::DST,
         )
         .to_affine();
 
-        let aggregated_signature = vec![msg * sk; S::SYNC_COMMITTEE_SIZE]
-            .into_iter()
+        let aggregated_signature = sks
+            .iter()
+            .map(|sk| msg * sk)
             .fold(G2::identity(), |acc, x| acc + x)
             .to_affine();
 
         let signature_compressed = aggregated_signature.to_compressed_be().to_vec();
 
-        let pubkey_uncompressed = (G1::generator() * sk)
-            .to_affine()
-            .to_uncompressed_be()
-            .to_vec();
+        let pubkeys_uncompressed = sks
+            .iter()
+            .map(|sk| {
+                (G1::generator() * sk)
+                    .to_affine()
+                    .to_uncompressed_be()
+                    .to_vec()
+            })
+            .collect_vec();
 
         Self {
             signature_compressed,
-            pubkeys_uncompressed: iter::repeat(pubkey_uncompressed)
-                .take(S::SYNC_COMMITTEE_SIZE)
-                .collect_vec(),
+            pubkeys_uncompressed,
             pariticipation_bits: vec![true; S::SYNC_COMMITTEE_SIZE],
             domain: DOMAIN,
             attested_header,