Crypto Audit Context

crypto-audit-context

Start here before claiming vulnerabilities.

Core principle: verify what the code actually enforces, not what the docs claim.

When to Use

• Beginning a ZK or cryptographic audit
• Reading unfamiliar verifier, prover, signature, DKG, or serialization code
• Building a threat model before bug hunting
• Prioritizing which files and functions deserve the deepest review first

When NOT to Use

• Verifying whether a specific suspected finding is a true positive
• Writing final severity decisions or report-ready findings
• Querying prior-art or disclosure state

Audit Priority

Review highest-risk code first:

1. Critical path — verify, batch_verify, deserialize, from_bytes, transcript/challenge generation, keygen, sign, prove
2. Trust boundary — unsafe blocks, FFI modules, unchecked constructors, parameter loading
3. Supporting — caches, zeroization, type conversions, error conversion, optimized backends

Rationalizations to Reject

| Rationalization | Why it is wrong | |---|---| | "The README explains the architecture" | READMEs describe intent, not enforcement | | "I'll map trust boundaries later during domain review" | Domain skills assume the dimension map is already built | | "The codebase is small, I can hold the context in my head" | Small codebases have the same attack-surface density |

Workflow

Phase 1: Map the critical path

• Identify verifier, transcript, parsing, and randomness entrypoints
• Mark code that handles attacker-controlled or externally supplied values

Phase 2: Build the dimension map

• Read references/dimensional-analysis.md
• Assign dimensions to values that cross trust boundaries
• Treat every unknown or inherited dimension as suspicious until proven safe

Phase 3: Build the protocol threat model

• Read references/threat-model-checklist.md
• Record replay surfaces, authentication roots, downgrade surfaces, and corruption model assumptions

Phase 4: Produce the audit handoff

• Summarize the highest-risk paths
• Name unresolved assumptions
• Hand off to a domain auditor or verification skill
• Initialize or update session state in zk-findings/sessions/.json

using zk-findings/sessions/session-state-schema.json

• Persist trust boundaries, open findings, and next-step routes so follow-on

conversations continue from the same state

Output Contract

Produce a context handoff that includes:

• Critical paths and trust boundaries that deserve deepest review
• Dimension-map anomalies and unresolved assumptions
• Threat-model notes that the next skill must preserve
• Recommended next skills, with a brief reason for each route
• Session state path updated in zk-findings/sessions/ for downstream handoffs

Reference Index

• [references/dimensional-analysis.md](references/dimensional-analysis.md)
• [references/threat-model-checklist.md](references/threat-model-checklist.md)

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Yue-Zhou1
• Source: Yue-Zhou1/zkcrypto-audit
• License: MIT

Install and usage instructions live in the source repository linked above.