Fiat Shamir Auditor

fiat-shamir-auditor

Domain auditor for transcript-binding and challenge-derivation correctness.

When to Use

• Reviewing Fiat-Shamir transforms in proof systems and signature schemes
• Auditing transcript absorb order and challenge derivation timing
• Checking public input and domain separation binding to transcript state
• Reviewing multi-round challenge dependencies in non-interactive protocols

When NOT to Use

• Hash primitive internals when transcript behavior is not under review
• Generic circuit checks with no transcript/challenge path
• Marking suspected transcript flaws as confirmed without verification gates

Core Review Areas

1. Transcript completeness for all prover and context messages
2. Domain separation across protocol rounds and contexts
3. Challenge derivation order and dependency correctness
4. Public input and statement binding to challenges
5. Multi-round transcript consistency and reset safety
6. Hash primitive suitability for challenge derivation

Workflow

Phase 1: Transcript inventory

• Read references/fiat-shamir-checklist.md
• Identify all absorb/squeeze operations and transcript states
• Enumerate every statement element expected to influence challenges

Phase 2: Binding review

• Execute workflows/transcript-binding-review.md
• Verify commitments are absorbed before challenge derivation
• Ensure public inputs and domain labels are bound at correct points

Phase 3: Pattern hunt

• Read references/finding-patterns.md
• Prioritize frozen-heart style independence, missing absorbs, and reset bugs

Phase 4: Handoff

• Send surviving findings to crypto-fp-check
• Use zkbugs-index only after verification succeeds

Output Contract

Produce a transcript-audit handoff that includes:

• The transcript states, labels, and challenge points involved
• The exact missing binding, absorb-order, or reset-safety issue
• Whether the issue affects soundness, replay resistance, or protocol context separation
• The next verification or reporting route

Reference Index

• references/fiat-shamir-checklist.md
• references/finding-patterns.md
• workflows/transcript-binding-review.md