folding-scheme-auditor

name	folding-scheme-auditor
description	Audit folding scheme and IVC implementations for accumulator soundness, step circuit binding, cycle-of-curves correctness, and running instance completeness. Use when reviewing Nova, HyperNova, ProtoStar, or custom folding-based proof systems in Rust.
allowed-tools	["Read","Grep","Glob","Bash"]

folding-scheme-auditor

Domain auditor for folding scheme and incrementally verifiable computation (IVC) systems.

When to Use

• Reviewing Nova, HyperNova, ProtoStar, or Sonobe-based Rust implementations
• Auditing accumulator update logic and relaxed R1CS folding equations
• Checking IVC step circuit binding and public input threading across steps
• Reviewing cycle-of-curves field selection and cross-curve consistency
• Auditing running instance completeness and error term construction

When NOT to Use

• Standard Groth16, PLONK, or STARKs without folding (use zk-circuit-auditor)
• Recursive plonky2/3 circuits (use zk-circuit-auditor + plonky2-patterns.md)
• Declaring accumulator bugs confirmed without crypto-fp-check

Core Review Areas

1. Accumulator soundness — relaxed R1CS folding equation correctness, error term construction and range
2. IVC step circuit binding — public input threading across steps, base case handling
3. Cycle-of-curves consistency — field element compatibility, cross-curve public input encoding
4. Running instance completeness — witness availability per step, error accumulation bounds
5. Folding verifier equation — cross-term commitments, challenge derivation, final SNARK proof

Workflow

Phase 1: Checklist pass

• Read references/folding-scheme-checklist.md
• Identify the folding scheme variant (Nova, HyperNova, ProtoStar) and the cycle of curves
• Map all accumulator update sites and IVC step boundaries

Phase 2: Accumulator review

• Execute workflows/accumulator-review.md
• Verify the relaxed R1CS equation, error term, and cross-term commitment at every folding step
• Treat any unchecked accumulator field as a soundness candidate until disproven

Phase 3: Pattern hunt

• Read references/finding-patterns.md
• Prioritize IVC step binding gaps, cycle-of-curves field mismatches, and base case soundness failures
• Check the final SNARK proof over the last accumulator for correct key binding

Phase 4: Handoff

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

Output Contract

Produce a folding-scheme handoff that includes:

• The accumulator state, step circuit, or verifier equation involved
• The exact folding equation gap, field mismatch, or binding failure
• Whether the issue is accumulator soundness, IVC threading, curve consistency, or verifier equation
• The next verification or reporting route

Reference Index

• references/folding-scheme-checklist.md
• references/finding-patterns.md
• workflows/accumulator-review.md