fhe-auditor

name	fhe-auditor
description	Audit FHE implementations for noise-budget accounting, bootstrapping correctness, modulus-switching safety, plaintext leakage, and key-switch parameter integrity.
allowed-tools	["Read","Grep","Glob","Bash"]

fhe-auditor

Domain auditor for fully homomorphic encryption pipelines and transform safety.

When to Use

• Auditing ciphertext lifecycle across FHE transforms
• Reviewing noise growth calculations and claimed depth limits
• Checking bootstrapping and key-switch correctness assumptions
• Verifying modulus switching and plaintext/ciphertext boundary handling

When NOT to Use

• Classical encryption reviews without homomorphic transforms
• Parameter-level lattice audits that do not involve FHE lifecycle behavior
• Confirming suspected FHE issues without verification gates

Core Review Areas

1. Ciphertext modulus transitions and switching semantics
2. Noise growth tracking and budget accounting
3. Bootstrapping parameter validity and correctness
4. Plaintext/ciphertext boundary and slot-packing isolation
5. Key-switch material provenance and application correctness

Workflow

Phase 1: Ciphertext lifecycle mapping

• Read references/fhe-checklist.md
• Execute workflows/noise-budget-review.md
• Map each ciphertext transform from encryption to final decrypt/consume step

Phase 2: Noise and transform review

• Validate noise-budget calculations at each transform stage
• Confirm bootstrapping refresh logic preserves security invariants
• Verify modulus and key-switch operations do not silently degrade correctness

Phase 3: Pattern hunt

• Read references/finding-patterns.md
• Prioritize exhausted noise budgets, precision drops, and leakage boundaries

Phase 4: Handoff

• Send surviving findings to crypto-fp-check
• Use zkbugs-index only after the finding survives verification

Output Contract

Produce an FHE-specific handoff that includes:

• The ciphertext lifecycle stage and transform under review
• The measured/claimed noise budget and correctness invariant at risk
• Whether the issue is noise, bootstrapping, modulus switch, key-switch, or leakage related
• The next verification or reporting route

Reference Index

• references/fhe-checklist.md
• references/finding-patterns.md
• workflows/noise-budget-review.md