---
title: "Deployed parameters that do not match the ceremony output"
description: "The verifying key deployed on-chain or shipped to clients differs from the ceremony result because of a rebuild, a manual copy, or a toolchain version change…"
type: "failure-mode"
url: "https://zkpick.com/ceremony/failure-modes/deployed-parameters-that-do-not-match-the-ceremony-output/"
section: "04 Running or reusing a trusted setup"
authors:
  - "MarketComp"
publisher: "MarketComp"
version: "1.3"
updated: "2026-09-12"
license: "CC-BY-4.0"
json: "https://zkpick.com/data/ceremony/failure-modes/deployed-parameters-that-do-not-match-the-ceremony-output.json"
---

*By MarketComp. Updated 2026-09-12. Version 1.3. CC BY 4.0.*

# Deployed parameters that do not match the ceremony output

The verifying key deployed on-chain or shipped to clients differs from the ceremony result because of a rebuild, a manual copy, or a toolchain version change — and nothing in the system detects it.

**Mitigation:** Pin the parameter hash in the verifier and in CI, and fail the build on mismatch. Include the check in the audit scope.