feat: optimize solidity honk verifier

Complete, without zk

Cuts off a million

next steps:
proof size has a large consequence with this one, due to memory expansion, so having a different proof type for the keccak one which does tighter serialisation will save a good chunk of gas - working on this next
- pr here #16018

Author: AztecBot

barretenberg/acir_tests/bootstrap.sh

@@ -152,6 +152,7 @@ function test_cmds {
   for t in assert_statement a_1_mul slices verify_honk_proof; do
     echo "$sol_prefix $scripts/bb_prove_sol_verify.sh $t --disable_zk"
     echo "$sol_prefix $scripts/bb_prove_sol_verify.sh $t"
+    echo "$sol_prefix USE_OPTIMIZED_CONTRACT=true $scripts/bb_prove_sol_verify.sh $t"
   done
   # prove with bb cli and verify with bb.js classes
   echo "$sol_prefix $scripts/bb_prove_bbjs_verify.sh a_1_mul"

barretenberg/acir_tests/scripts/bb_prove_sol_verify.sh

@@ -16,6 +16,13 @@ for arg in "$@"; do
     flags+=" $arg"
 done
 
+USE_OPTIMIZED_CONTRACT=${USE_OPTIMIZED_CONTRACT:-false}
+
+write_contract_flags=$flags
+if [[ -z "$USE_OPTIMIZED_CONTRACT" ]]; then
+    write_contract_flags+=" --optimized"
+fi
+
 # Check if --disable_zk is in the flags to determine HAS_ZK
 if [[ "$flags" == *"--disable_zk"* ]]; then
     has_zk="false"
@@ -29,7 +36,7 @@ trap "rm -rf output-$$" EXIT
 # Create a proof, write the solidity contract, write the proof as fields in order to extract the public inputs
 $bb prove $flags -b target/program.json --oracle_hash keccak --output_format bytes_and_fields --write_vk -o output-$$
 $bb verify $flags --oracle_hash keccak -i output-$$/public_inputs -k output-$$/vk -p output-$$/proof
-$bb write_solidity_verifier $flags -k output-$$/vk -o output-$$/Verifier.sol
+$bb write_solidity_verifier $write_contract_flags -k output-$$/vk -o output-$$/Verifier.sol
 
 # Use solcjs to compile the generated key contract with the template verifier and test contract
 # index.js will start an anvil, on a random port

barretenberg/acir_tests/sol-test/HonkTest.sol

@@ -12,7 +12,7 @@ contract Test {
         verifier = new HonkVerifier();
     }
 
-    function test(bytes calldata proof, bytes32[] calldata publicInputs) public view returns (bool) {
+    function test(bytes calldata proof, bytes32[] calldata publicInputs) public returns (bool) {
         return verifier.verify(proof, publicInputs);
     }
 }

barretenberg/acir_tests/sol-test/src/index.js

@@ -274,6 +274,9 @@ try {
         // Deploy the library
         console.log("Deploying ZKTranscriptLib library...");
         const libraryAddress = await deploy(signer, libraryAbi, libraryBytecode);
+
+        // Wait for the library deployment - for some reason we have an issue with nonces here
+        await new Promise((resolve) => setTimeout(resolve, 500));
         console.log("ZKTranscriptLib deployed at:", libraryAddress);
 
         // Link the library to the verifier bytecode

barretenberg/cpp/src/barretenberg/api/api.hpp

@@ -25,6 +25,8 @@ class API {
         bool slow_low_memory{ false };          // use file backed memory for polynomials
         bool update_inputs{ false };            // update inputs when check fails
 
+        bool optimized_solidity_verifier{ false }; // should we use the optimized sol verifier? (temp)
+
         friend std::ostream& operator<<(std::ostream& os, const Flags& flags)
         {
             os << "flags: [\n"

barretenberg/cpp/src/barretenberg/api/api_ultra_honk.cpp

@@ -8,6 +8,7 @@
 #include "barretenberg/dsl/acir_format/acir_to_constraint_buf.hpp"
 #include "barretenberg/dsl/acir_format/proof_surgeon.hpp"
 #include "barretenberg/dsl/acir_proofs/honk_contract.hpp"
+#include "barretenberg/dsl/acir_proofs/honk_optimized_contract.hpp"
 #include "barretenberg/dsl/acir_proofs/honk_zk_contract.hpp"
 #include "barretenberg/honk/proof_system/types/proof.hpp"
 #include "barretenberg/numeric/uint256/uint256.hpp"
@@ -236,7 +237,8 @@ void UltraHonkAPI::write_solidity_verifier(const Flags& flags,
     // Convert flags to ProofSystemSettings
     bbapi::ProofSystemSettings settings{ .ipa_accumulation = flags.ipa_accumulation,
                                          .oracle_hash_type = flags.oracle_hash_type,
-                                         .disable_zk = flags.disable_zk };
+                                         .disable_zk = flags.disable_zk,
+                                         .optimized_solidity_verifier = flags.optimized_solidity_verifier };
 
     // Execute solidity verifier command
     auto response = bbapi::CircuitWriteSolidityVerifier{ .verification_key = vk_bytes, .settings = settings }.execute();

barretenberg/cpp/src/barretenberg/bb/cli.cpp

@@ -282,6 +282,11 @@ int parse_and_run_cli_command(int argc, char* argv[])
         return subcommand->add_flag("--update_inputs", flags.update_inputs, "Update inputs if vk check fails.");
     };
 
+    const auto add_optimized_solidity_verifier_flag = [&](CLI::App* subcommand) {
+        return subcommand->add_flag(
+            "--optimized", flags.optimized_solidity_verifier, "Use the optimized Solidity verifier.");
+    };
+
     bool print_op_counts = false;
     const auto add_print_op_counts_flag = [&](CLI::App* subcommand) {
         return subcommand->add_flag("--print_op_counts", print_op_counts, "Print op counts to json on one line.");
@@ -412,6 +417,7 @@ int parse_and_run_cli_command(int argc, char* argv[])
     add_verbose_flag(write_solidity_verifier);
     remove_zk_option(write_solidity_verifier);
     add_crs_path_option(write_solidity_verifier);
+    add_optimized_solidity_verifier_flag(write_solidity_verifier);
 
     /***************************************************************************************************************
      * Subcommand: OLD_API

barretenberg/cpp/src/barretenberg/bbapi/bbapi_shared.hpp

@@ -92,7 +92,10 @@ struct ProofSystemSettings {
      */
     bool disable_zk = false;
 
-    MSGPACK_FIELDS(ipa_accumulation, oracle_hash_type, disable_zk);
+    // TODO(md): remove this once considered stable
+    bool optimized_solidity_verifier = false;
+
+    MSGPACK_FIELDS(ipa_accumulation, oracle_hash_type, disable_zk, optimized_solidity_verifier);
     bool operator==(const ProofSystemSettings& other) const = default;
 };
 

barretenberg/cpp/src/barretenberg/bbapi/bbapi_ultra_honk.cpp

@@ -9,6 +9,7 @@
 #include "barretenberg/dsl/acir_format/acir_to_constraint_buf.hpp"
 #include "barretenberg/dsl/acir_format/serde/witness_stack.hpp"
 #include "barretenberg/dsl/acir_proofs/honk_contract.hpp"
+#include "barretenberg/dsl/acir_proofs/honk_optimized_contract.hpp"
 #include "barretenberg/dsl/acir_proofs/honk_zk_contract.hpp"
 #include "barretenberg/flavor/mega_flavor.hpp"
 #include "barretenberg/flavor/ultra_flavor.hpp"
@@ -340,8 +341,17 @@ CircuitWriteSolidityVerifier::Response CircuitWriteSolidityVerifier::execute(BB_
 {
     using VK = UltraKeccakFlavor::VerificationKey;
     auto vk = std::make_shared<VK>(from_buffer<VK>(verification_key));
+
     std::string contract = settings.disable_zk ? get_honk_solidity_verifier(vk) : get_honk_zk_solidity_verifier(vk);
 
+// If in wasm, we dont include the optimized solidity verifier - due to its large bundle size
+// This will run generate twice, but this should only be run before deployment and not frequently
+#ifndef __wasm__
+    if (settings.disable_zk && settings.optimized_solidity_verifier) {
+        contract = get_optimized_honk_solidity_verifier(vk);
+    }
+#endif
+
     return { std::move(contract) };
 }
 

barretenberg/cpp/src/barretenberg/dsl/acir_proofs/honk_contract.hpp

@@ -15,7 +15,7 @@ static const char HONK_CONTRACT_SOURCE[] = R"(
 pragma solidity ^0.8.27;
 
 interface IVerifier {
-    function verify(bytes calldata _proof, bytes32[] calldata _publicInputs) external view returns (bool);
+    function verify(bytes calldata _proof, bytes32[] calldata _publicInputs) external returns (bool);
 }
 
 type Fr is uint256;
@@ -68,7 +68,7 @@ library FrLib {
             mstore(add(free, 0x20), 0x20)
             mstore(add(free, 0x40), 0x20)
             mstore(add(free, 0x60), v)
-            mstore(add(free, 0x80), sub(MODULUS, 2))
+            mstore(add(free, 0x80), sub(MODULUS, 2)) 
             mstore(add(free, 0xa0), MODULUS)
             let success := staticcall(gas(), 0x05, free, 0xc0, 0x00, 0x20)
             if iszero(success) {
@@ -92,7 +92,7 @@ library FrLib {
             mstore(add(free, 0x20), 0x20)
             mstore(add(free, 0x40), 0x20)
             mstore(add(free, 0x60), b)
-            mstore(add(free, 0x80), v)
+            mstore(add(free, 0x80), v) 
             mstore(add(free, 0xa0), MODULUS)
             let success := staticcall(gas(), 0x05, free, 0xc0, 0x00, 0x20)
             if iszero(success) {
@@ -674,6 +674,7 @@ library RelationsLib {
         accumulateNnfRelation(purportedEvaluations, evaluations, powPartialEval);
         accumulatePoseidonExternalRelation(purportedEvaluations, evaluations, powPartialEval);
         accumulatePoseidonInternalRelation(purportedEvaluations, evaluations, powPartialEval);
+
         // batch the subrelations with the alpha challenges to obtain the full honk relation
         accumulator = scaleAndBatchSubrelations(evaluations, alphas);
     }
@@ -1051,7 +1052,7 @@ library RelationsLib {
         ap.index_delta = wire(p, WIRE.W_L_SHIFT) - wire(p, WIRE.W_L);
         ap.record_delta = wire(p, WIRE.W_4_SHIFT) - wire(p, WIRE.W_4);
 
-        ap.index_is_monotonically_increasing = ap.index_delta * ap.index_delta - ap.index_delta; // deg 2
+        ap.index_is_monotonically_increasing = ap.index_delta * (ap.index_delta - Fr.wrap(1)); // deg 2
 
         ap.adjacent_values_match_if_adjacent_indices_match = (ap.index_delta * MINUS_ONE + ONE) * ap.record_delta; // deg 2
 
@@ -1082,7 +1083,7 @@ library RelationsLib {
          * with a WRITE operation.
          */
         Fr access_type = (wire(p, WIRE.W_4) - ap.partial_record_check); // will be 0 or 1 for honest Prover; deg 1 or 4
-        ap.access_check = access_type * access_type - access_type; // check value is 0 or 1; deg 2 or 8
+        ap.access_check = access_type * (access_type - Fr.wrap(1)); // check value is 0 or 1; deg 2 or 8
 
         // reverse order we could re-use `ap.partial_record_check`  1 -  ((w3' * eta + w2') * eta + w1') * eta
         // deg 1 or 4
@@ -1256,7 +1257,7 @@ library RelationsLib {
     function accumulatePoseidonExternalRelation(
         Fr[NUMBER_OF_ENTITIES] memory p,
         Fr[NUMBER_OF_SUBRELATIONS] memory evals,
-        Fr domainSep // i guess this is the scaling factor?
+        Fr domainSep
     ) internal pure {
         PoseidonExternalParams memory ep;
 
@@ -1354,7 +1355,7 @@ library RelationsLib {
         Fr[NUMBER_OF_SUBRELATIONS] memory evaluations,
         Fr[NUMBER_OF_ALPHAS] memory subrelationChallenges
     ) internal pure returns (Fr accumulator) {
-        accumulator = accumulator + evaluations[0];
+        accumulator = evaluations[0];
 
         for (uint256 i = 1; i < NUMBER_OF_SUBRELATIONS; ++i) {
             accumulator = accumulator + evaluations[i] * subrelationChallenges[i - 1];
@@ -1421,10 +1422,9 @@ library CommitmentSchemeLib {
             );
             // Divide by the denominator
             batchedEvalRoundAcc = batchedEvalRoundAcc * (challengePower * (ONE - u) + u).invert();
-            if (i <= logSize) {
-                batchedEvalAccumulator = batchedEvalRoundAcc;
-                foldPosEvaluations[i - 1] = batchedEvalRoundAcc;
-            }
+
+            batchedEvalAccumulator = batchedEvalRoundAcc;
+            foldPosEvaluations[i - 1] = batchedEvalRoundAcc;
         }
         return foldPosEvaluations;
     }
@@ -2073,27 +2073,24 @@ abstract contract BaseHonkVerifier is IVerifier {
         // Compute Shplonk constant term contributions from Aₗ(± r^{2ˡ}) for l = 1, ..., m-1;
         // Compute scalar multipliers for each fold commitment
         for (uint256 i = 0; i < $LOG_N - 1; ++i) {
-            bool dummy_round = i >= ($LOG_N - 1);
-
-            if (!dummy_round) {
-                // Update inverted denominators
-                mem.posInvertedDenominator = (tp.shplonkZ - powers_of_evaluation_challenge[i + 1]).invert();
-                mem.negInvertedDenominator = (tp.shplonkZ + powers_of_evaluation_challenge[i + 1]).invert();
-
-                // Compute the scalar multipliers for Aₗ(± r^{2ˡ}) and [Aₗ]
-                mem.scalingFactorPos = mem.batchingChallenge * mem.posInvertedDenominator;
-                mem.scalingFactorNeg = mem.batchingChallenge * tp.shplonkNu * mem.negInvertedDenominator;
-                // [Aₗ] is multiplied by -v^{2l}/(z-r^{2^l}) - v^{2l+1} /(z+ r^{2^l})
-                scalars[NUMBER_UNSHIFTED + 1 + i] = mem.scalingFactorNeg.neg() + mem.scalingFactorPos.neg();
-
-                // Accumulate the const term contribution given by
-                // v^{2l} * Aₗ(r^{2ˡ}) /(z-r^{2^l}) + v^{2l+1} * Aₗ(-r^{2ˡ}) /(z+ r^{2^l})
-                Fr accumContribution = mem.scalingFactorNeg * proof.geminiAEvaluations[i + 1];
-                accumContribution = accumContribution + mem.scalingFactorPos * foldPosEvaluations[i + 1];
-                mem.constantTermAccumulator = mem.constantTermAccumulator + accumContribution;
-                // Update the running power of v
-                mem.batchingChallenge = mem.batchingChallenge * tp.shplonkNu * tp.shplonkNu;
-            }
+            // Update inverted denominators
+            mem.posInvertedDenominator = (tp.shplonkZ - powers_of_evaluation_challenge[i + 1]).invert();
+            mem.negInvertedDenominator = (tp.shplonkZ + powers_of_evaluation_challenge[i + 1]).invert();
+
+            // Compute the scalar multipliers for Aₗ(± r^{2ˡ}) and [Aₗ]
+            mem.scalingFactorPos = mem.batchingChallenge * mem.posInvertedDenominator;
+            mem.scalingFactorNeg = mem.batchingChallenge * tp.shplonkNu * mem.negInvertedDenominator;
+            // [Aₗ] is multiplied by -v^{2l}/(z-r^{2^l}) - v^{2l+1} /(z+ r^{2^l})
+            scalars[NUMBER_UNSHIFTED + 1 + i] = mem.scalingFactorNeg.neg() + mem.scalingFactorPos.neg();
+
+            // Accumulate the const term contribution given by
+            // v^{2l} * Aₗ(r^{2ˡ}) /(z-r^{2^l}) + v^{2l+1} * Aₗ(-r^{2ˡ}) /(z+ r^{2^l})
+            Fr accumContribution = mem.scalingFactorNeg * proof.geminiAEvaluations[i + 1];
+
+            accumContribution = accumContribution + mem.scalingFactorPos * foldPosEvaluations[i + 1];
+            mem.constantTermAccumulator = mem.constantTermAccumulator + accumContribution;
+            // Update the running power of v
+            mem.batchingChallenge = mem.batchingChallenge * tp.shplonkNu * tp.shplonkNu;
 
             commitments[NUMBER_UNSHIFTED + 1 + i] = proof.geminiFoldComms[i];
         }