mpc-auditor

name	mpc-auditor
description	Audit MPC implementations for garbled-circuit integrity, oblivious transfer misuse, share validation, Beaver triple authenticity, and transcript/session binding issues.
allowed-tools	["Read","Grep","Glob","Bash"]

mpc-auditor

Domain auditor for multi-party computation protocols and transcript integrity.

When to Use

• Auditing garbled-circuit protocol implementations
• Reviewing oblivious transfer role and consistency checks
• Checking share validation before reconstruction
• Reviewing Beaver triple generation and authenticity guarantees
• Verifying transcript/session binding across rounds

When NOT to Use

• Single-party cryptographic primitive audits without MPC coordination
• Pure circuit-constraint analysis without multi-party communication/state
• Confirming suspected findings without verification gates

Core Review Areas

1. Participant authentication and role binding
2. Transcript/session separation across rounds and retries
3. OT input consistency and sender/receiver role correctness
4. Share MAC/commitment checks before reconstruction
5. Offline/online phase separation and Beaver triple authenticity

Workflow

Phase 1: Protocol phase mapping

• Read references/mpc-checklist.md
• Execute workflows/share-validation-review.md
• Enumerate setup, offline, and online phases for each participant role

Phase 2: Share and transcript review

• Verify share validation occurs before any reconstruction logic
• Confirm transcript identifiers are session-specific and replay-resistant
• Validate participant role binding in all message handlers

Phase 3: Pattern hunt

• Read references/finding-patterns.md
• Prioritize unchecked share use, OT role confusion, and unauthenticated triples

Phase 4: Handoff

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

Output Contract

Produce an MPC-specific handoff that includes:

• The protocol phase and participant role involved
• The transcript/session binding or share-validation invariant at risk
• Whether the issue is OT, share, triple, garbled-circuit, or reconstruction related
• The next verification or reporting route

Reference Index

• references/mpc-checklist.md
• references/finding-patterns.md
• workflows/share-validation-review.md