hash-function-auditor

name	hash-function-auditor
description	Audit ZK-friendly hash functions (Poseidon, Rescue, MiMC, Pedersen) for parameter selection, sponge construction, domain separation, and algebraic attack resistance.
allowed-tools	["Read","Grep","Glob","Bash"]

hash-function-auditor

Domain auditor for ZK-friendly hash primitive security and usage correctness.

When to Use

• Auditing Poseidon, Rescue, MiMC, Pedersen, or related ZK hash implementations
• Reviewing sponge absorption/squeezing APIs and parameterization
• Verifying domain separation tags across hash call sites
• Checking round count and matrix choices against claimed security margins

When NOT to Use

• Generic transcript review not focused on hash primitive internals
• Commitment opening verification without hash primitive concerns
• Marking hash findings as confirmed without verification gates

Core Review Areas

1. Parameter selection and provenance
2. Sponge construction and capacity/rate safety
3. Domain separation and call-site context binding
4. Algebraic attack resistance for chosen rounds and constants
5. Matrix and S-box structural properties

Workflow

Phase 1: Parameter provenance review

• Read references/hash-checklist.md
• Verify round constants and MDS matrices are derived with clear provenance
• Confirm claimed security level matches round configuration

Phase 2: Sponge and API review

• Execute workflows/sponge-review.md
• Validate absorption/squeezing behavior, padding, and capacity boundaries
• Review call sites for unsafe reuse across protocol domains

Phase 3: Pattern hunt

• Read references/finding-patterns.md
• Prioritize weak constants, missing domain separation, and capacity misuse

Phase 4: Handoff

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

Output Contract

Produce a hash-audit handoff that includes:

• The primitive, parameter set, and call sites under review
• The exact security-property gap (capacity, rounds, separation, algebraic margin)
• The exploitability conditions and expected impact
• The next verification or reporting route

Reference Index

• references/hash-checklist.md
• references/finding-patterns.md
• workflows/sponge-review.md