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03 — Auditing · Assurance guide

Verifier and integration review

Human review

In one paragraph

Verifier and integration review: Human review. Layer: Verifier / on-chain. Characteristic finds: Public-input aliasing and encoding mismatch, replay, verifying-key drift, missing point checks. Blind to: Circuit-internal soundness. Coverage claim: None — but the code is small. Cost profile: Low; conventional review skills. Choose it when: Every deployment. Assign one party explicit ownership of the circuit-to-verifier boundary, and require them to check the deployed verifying key against a reproducible build of the audited circuit.

By MarketComp Updated v1.3 About the authors Changelog
Layer
Verifier / on-chain
Characteristic finds
Public-input aliasing and encoding mismatch, replay, verifying-key drift, missing point checks
Blind to
Circuit-internal soundness
Coverage claim
None — but the code is small
Cost profile
Low; conventional review skills
Assurance matrix · see the row in context

What it is

Review of everything between a valid proof and a state change: the verifier contract or host routine, public input encoding and ordering, field-range validation, verifying-key provenance and immutability, nullifier storage and replay logic, upgrade authority, and the binding between the deployed key and the audited circuit. This is where circuit-correct systems still fail.

Strengths and tradeoffs

Strengths
  • Covers a bug class that circuit tooling structurally cannot see
  • Relatively cheap and fast — the code is small and conventional
  • Reuses well-developed smart-contract audit practice and tooling
  • Directly addresses the highest-frequency deployment failures
Tradeoffs
  • Often split across two engagements with the seam owned by nobody — and the seam is where encoding mismatches live
  • Generated verifier code is assumed correct because a tool produced it — yet generated verifiers have shipped without a field-modulus check on public signals, the input-aliasing bug
  • Cannot be done meaningfully without the circuit's public-input specification

Choose it whenEvery deployment. Assign one party explicit ownership of the circuit-to-verifier boundary, and require them to check the deployed verifying key against a reproducible build of the audited circuit.

Failure modes that involve it
Direct answers that mention it
Maintained implementations

Not recorded for this entry.

Maturity: Production standard · License: Service · github.com ↗

How to decide
Other assurance guides in §03
ZK security consultanciesManual circuit and constraint reviewAutomated underconstraint detectionFormal verification of ZK circuitsDifferential and fuzz testingCryptographic review of the protocol and proof systemAudit contestsBug bountiesLLM-assisted review

Sources cited on this page · 1

  1. snarkjs #358 — public signals not checked against the field modulus (input aliasing)issue

All 48 sources for §03 are listed on the section page →

Cite this page 
MarketComp (2026). Verifier and integration review. The ZK Field Manual (Version 1.3). MarketComp. https://zkpick.com/audit/verifier-review/
@misc{zkfieldmanual-verifier-and-integration-review,
  title        = {Verifier and integration review — The ZK Field Manual},
  author       = {MarketComp},
  year         = {2026},
  version      = {1.3},
  howpublished = {\url{https://zkpick.com/audit/verifier-review/}},
  note         = {Accessed: YYYY-MM-DD}
}