mega_zk_flavor.hpp

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// === AUDIT STATUS ===
// internal:    { status: Completed, auditors: [Sergei], commit: }
// external_1:  { status: not started, auditors: [], commit: }
// external_2:  { status: not started, auditors: [], commit: }
// =====================
 
#pragma once
 
#include "barretenberg/constants.hpp"
#include "barretenberg/flavor/mega_flavor.hpp"
 
namespace bb {
 
class MegaZKFlavor : public bb::MegaFlavor {
  public:
    // MegaZK is only used in production to prove the Hiding Kernel
    static constexpr size_t VIRTUAL_LOG_N = HIDING_KERNEL_LOG_N;
 
    // Indicates that this flavor runs with ZK Sumcheck.
    static constexpr bool HasZK = true;
 
    // ZK masking lives at rows [NUM_ZERO_ROWS, TRACE_OFFSET); Sumcheck disables rows [0, TRACE_OFFSET).
    static constexpr size_t TRACE_OFFSET = NUM_DISABLED_ROWS_IN_SUMCHECK;
 
    // MegaZK does not include a Gemini masking polynomial in its entities; the translator provides one
    // at the correct joint circuit size in the batched Chonk flow.
    static constexpr bool HasGeminiMasking = false;
 
    // The degree has to be increased because the relation is multiplied by the Row Disabling Polynomial
    static constexpr size_t BATCHED_RELATION_PARTIAL_LENGTH = MegaFlavor::BATCHED_RELATION_PARTIAL_LENGTH + 1;
    static_assert(BATCHED_RELATION_PARTIAL_LENGTH == Curve::LIBRA_UNIVARIATES_LENGTH,
                  "LIBRA_UNIVARIATES_LENGTH must be equal to MegaZKFlavor::BATCHED_RELATION_PARTIAL_LENGTH");
 
    // Shplemini's remove_repeated_commitments uses offset = HasZK ? 2 : 1. Since MegaZK has HasZK=true
    // but no masking poly in its entities, the offset is 1 larger than the actual entity layout.
    // Compensate by shifting indices by -1 relative to MegaFlavor's REPEATED_COMMITMENTS.
    static constexpr RepeatedCommitmentsData REPEATED_COMMITMENTS = RepeatedCommitmentsData(
        NUM_PRECOMPUTED_ENTITIES - 1, NUM_PRECOMPUTED_ENTITIES + NUM_WITNESS_ENTITIES - 1, NUM_SHIFTED_ENTITIES);
 
    // Size of the final PCS MSM for ZK = non-ZK size + NUM_LIBRA_COMMITMENTS (3)
    static constexpr size_t FINAL_PCS_MSM_SIZE(size_t log_n = VIRTUAL_LOG_N)
    {
        return NUM_UNSHIFTED_ENTITIES + log_n + 2 + NUM_LIBRA_COMMITMENTS;
    }
 
    using Transcript = NativeTranscript;
    using VKAndHash = MegaFlavor::VKAndHash;
};
 
} // namespace bb