Pqc-scan: scan your codebase for quantum-vulnerable cryptography

A new open-source static analysis tool called pqc-scan helps developers find quantum-vulnerable cryptography in their codebases before quantum computers become a threat. The tool scans source code, configurations, and dependencies for algorithms like RSA and ECDSA that are broken by Shor's algorithm, and recommends migration to NIST-standardized post-quantum algorithms such as ML-KEM and ML-DSA.

Snyk for Post-Quantum Cryptography — a developer-first static analysis tool that finds quantum-vulnerable cryptography in your code, configs, and dependencies before quantum computers or your auditors do. pqc-scan is zero-friction and lives where your code lives: in your editor, on the command line, and right inside your pull requests. It parses real source with tree-sitter ASTs not brittle regexes , tells you exactly which line is vulnerable, why it matters, and how to migrate to a NIST-standardized post-quantum algorithm. pqc-scan scan . pqc-scan · Post-Quantum Cryptography scan ✖ CRITICAL PQC001 · RSA Key Generation high confidence ┌─ app/keys.py:10:19 RSA-2048 │ rsa.generate private key │ public exponent=65537, │ key size=2048, │ └─ RSA key generation detected. RSA is broken by Shor's algorithm on a cryptographically relevant quantum computer, regardless of key size. Migrate to: ML-KEM-768 CRYSTALS-Kyber … · FIPS 203 ML-KEM / FIPS 204 ML-DSA see: https://csrc.nist.gov/pubs/fips/203/final ──────────────────────────────────────────────────────────────────────────────── Critical: 2 High: 2 Medium: 0 Low: 0 | Total findings: 4 Files scanned: 1 | Time: 0.00s The public-key cryptography that secures almost everything online — TLS handshakes, SSH, code signing, JWTs, certificates, VPNs — relies on math problems that are hard for classical computers . Shor's algorithm , run on a cryptographically relevant quantum computer, solves all of them efficiently. That breaks, completely: RSA any key size, including RSA-4096 Elliptic-curve crypto : ECDSA, ECDH/ECDHE, X25519/X448, Ed25519/Ed448 Finite-field crypto : Diffie-Hellman DH/DHE , DSA Symmetric crypto and hashing are weakened but not broken: Grover's algorithm only halves the effective security level, so AES-256 and SHA-256/SHA3-256 remain safe. You don't need a quantum computer to exist today to be at risk. Adversaries can capture encrypted traffic now and decrypt it later once quantum hardware matures. Any data with a long confidentiality lifetime — health records, financial data, state secrets, long-lived credentials — is already exposed. Key-exchange material ECDH, X25519, DH is the prime target. August 2024 — NIST finalized the first post-quantum standards: FIPS 203 ML-KEM for key encapsulation, FIPS 204 ML-DSA and FIPS 205 SLH-DSA for digital signatures. 2030 / 2035 — US federal guidance CNSA 2.0, NSM-10 sets a migration deadline: begin now, complete the transition for most systems by 2030 , finish by 2035. Migration is a multi-year inventory-and-replace effort. pqc-scan is the inventory step you can run on every commit. pqc-scan requires Python ≥ 3.10 . Install editable from a clone of the source: git clone https://github.com/pqc-scan/pqc-scan.git cd pqc-scan pip install -e . This installs the pqc-scan console script. Verify: pqc-scan --version pqc-scan 0.1.0 For development tests + coverage : pip install -e ". dev " pytest All scanning dependencies tree-sitter grammars for Python, JavaScript, Java, Go, plus Typer, Rich and PyYAML are installed automatically — there is no native toolchain to build. pqc-scan scan . scan the current tree, pretty console report pqc-scan scan src/ -s high only report HIGH and CRITICAL findings pqc-scan scan . -o sarif -f out.sarif write SARIF for GitHub code scanning pqc-scan scan . --changed-only only files changed in the current git diff pqc-scan rules list every detection rule pqc-scan init write a starter .pqcscan.yml pqc-scan exposes four commands: scan , report , init , and rules . pqc-scan scan PATH OPTIONS PATH defaults to . the current directory and may be a file or a directory. | Flag | Alias | Description | |---|---|---| --output | -o | Output format: console default , sarif , cbom , json . | --output-file | -f | Write output to this file instead of stdout. | --severity | -s | Minimum severity to report: critical , high , medium , low . | --exclude | Glob pattern to exclude. Repeatable. | | --changed-only | Only scan files changed in the current git diff fast PR scans . | | --config | Path to a .pqcscan.yml config file. | | --no-color | Disable colored output auto-disabled when writing to a file . | | --fail-on-findings | Exit with code 1 if any findings are reported — for CI gating. | | --limit N | Show at most N findings in console output 0 = all . | | --summary | Console output: totals and a per-file breakdown only, no per-finding detail. | | --group-by | Console grouping: severity default or file . | Examples: Console report, but gate CI: non-zero exit if anything is found. pqc-scan scan . --fail-on-findings Scan only application code, skip tests and vendored code. pqc-scan scan . --exclude " /tests/ " --exclude " /third party/ " Emit machine-readable JSON to stdout pipe into jq, dashboards, etc. . pqc-scan scan src/ -o json Only audit what this branch changed, at HIGH severity and above. pqc-scan scan . --changed-only -s high --fail-on-findings Large repo? Get the overview first, then drill into one file at a time. pqc-scan scan . --summary pqc-scan scan . --group-by file --limit 50 Example console output scanning a single file : pqc-scan · Post-Quantum Cryptography scan ✖ CRITICAL PQC001 · RSA Key Generation high confidence ┌─ app/keys.py:10:19 RSA-2048 │ rsa.generate private key │ public exponent=65537, │ key size=2048, │ └─ RSA key generation detected. RSA is broken by Shor's algorithm on a cryptographically relevant quantum computer, regardless of key size. Migrate to: ML-KEM-768 CRYSTALS-Kyber for encryption / key establishment, or ML-DSA-65 … · FIPS 203 ML-KEM / FIPS 204 ML-DSA see: https://csrc.nist.gov/pubs/fips/203/final ⚠ HIGH PQC002 · RSA Encryption / Padding high confidence ┌─ app/keys.py:26:9 RSA-OAEP │ padding.OAEP │ mgf=padding.MGF1 algorithm=hashes.SHA256 , │ algorithm=hashes.SHA256 , │ label=None, │ └─ RSA-based encryption or padding OAEP / PKCS1v15 detected. RSA encryption is broken by Shor's algorithm. Migrate to: ML-KEM-768 CRYSTALS-Kyber · FIPS 203 see: https://csrc.nist.gov/pubs/fips/203/final ──────────────────────────────────────────────────────────────────────────────── Critical: 2 High: 2 Medium: 0 Low: 0 | Total findings: 4 Files scanned: 1 | Time: 0.00s report runs a scan and writes a machine-readable artifact to disk. Unlike scan , the format defaults to cbom and --output-file is required . pqc-scan report PATH --output-file FILE --format cbom|sarif|json --config FILE Generate a CycloneDX Cryptography Bill of Materials. pqc-scan report . --output-file cbom.json Generate a SARIF report for archival / upload. pqc-scan report . --format sarif --output-file results.sarif pqc-scan init PATH --force Writes a starter .pqcscan.yml to PATH default . . Refuses to overwrite an existing file unless --force is given. pqc-scan init Created .pqcscan.yml pqc-scan rules Prints a table of every rule ID, name, severity, category, description . pqc-scan ships 14 rules , covering quantum-vulnerable key generation, signatures, encryption, key exchange, hashing, weak JWT/TLS configuration, legacy ciphers, and quantum-vulnerable dependencies. | ID | Name | Severity | Category | |---|---|---|---| PQC001 | RSA Key Generation | critical | key-generation | PQC002 | RSA Encryption / Padding | high | encryption | PQC003 | RSA Signature | critical | signing | PQC004 | ECDSA Key Generation or Signing | critical | signing | PQC005 | ECDH / X25519 Key Exchange | high | key-exchange | PQC006 | Ed25519 / Ed448 Key Generation | high | signing | PQC007 | Diffie-Hellman Key Exchange | high | key-exchange | PQC008 | DSA Key Generation or Signing | critical | signing | PQC009 | SHA-1 Usage | medium | hashing | PQC010 | MD5 Usage | high | hashing | PQC011 | Weak JWT Algorithm RS/ES/PS | high | signing | PQC012 | Weak TLS Configuration | medium | configuration | PQC013 | DES / 3DES Usage | high | encryption | PQC014 | Quantum-Vulnerable Dependency | medium | dependency | Run pqc-scan rules for the full descriptions and to confirm the set installed on your machine. Supported languages code : Python, JavaScript/TypeScript, Java, Go. Supported manifests/configs: requirements.txt , package.json , plus YAML / JSON / TOML / .conf configuration files TLS, JWT, cipher lists . Library coverage highlights beyond the language standard libraries : Python — cryptography hazmat , pycryptodome/pycrypto RSA.generate , pkcs1 15 , pss , DSS , PKCS1 OAEP , pyOpenSSL TYPE RSA , paramiko, PyJWT / python-jose, ssl , hashlib including hashlib.new "sha1" and the usedforsecurity=False demotion to low . JavaScript — Node crypto generateKeyPair , createDiffieHellman , publicEncrypt , createSign , WebCrypto SubtleCrypto , jsonwebtoken , jose setProtectedHeader , node-forge, AWS KMS asymmetric KeySpec s. Java — JCA factories KeyPairGenerator , Signature , Cipher , MessageDigest , KeyAgreement , Bouncy Castle lightweight API RSAKeyGenerationParameters , ECDSASigner , Ed25519Signer , … , and SSLContext.getInstance with legacy protocols. Go — crypto/rsa , crypto/ecdsa , crypto/ecdh , crypto/ed25519 , crypto/dsa , crypto/tls configuration MinVersion pins and weak CipherSuites , x/crypto/curve25519 , and golang-jwt signing methods. Context hints. Findings inside code that looks like crypto-library plumbing paths containing hazmat , internal , backends , vendor , … or inside a generate key -style wrapper carry a context hint explaining whether the call site is actionable for you or belongs to a library you merely consume. Hints appear in console output, SARIF properties.contextHint , and the JSON context hint field. Choose with -o / --output on scan , or --format on report . A colorized, human-readable report with severity badges, the exact code snippet, the migration target, and the relevant NIST standard. Color is auto-disabled when writing to a file or with --no-color . Static Analysis Results Interchange Format 2.1.0 . Upload it with the CodeQL action and findings appear as inline annotations on the exact line in pull requests and in the repository's Security → Code scanning tab. pqc-scan scan . -o sarif -f pqc-scan.sarif { "$schema": "https://raw.githubusercontent.com/oasis-tcs/sarif-spec/.../sarif-schema-2.1.0.json", "version": "2.1.0", "runs": { "tool": { "driver": { "name": "pqc-scan", "version": "0.1.0", "rules": ... } }, "results": ... } } A CycloneDX 1.6 CBOM : a structured inventory of every cryptographic asset found, emitted as cryptographic-asset components. Ideal for compliance, supply-chain attestation, and tracking migration progress over time. pqc-scan report . --format cbom --output-file cbom.json { "bomFormat": "CycloneDX", "specVersion": "1.6", "components": { "type": "cryptographic-asset", "name": "RSA-2048", "...": "..." } } Scan metadata plus every finding with full migration metadata — easy to pipe into jq , dashboards, or custom tooling. pqc-scan scan . -o json | jq '.findings | {rule id, severity, file path, line number, algorithm}' { "tool": "pqc-scan", "version": "0.1.0", "generated at": "2026-07-06T12:00:00Z", "paths": "/repo" , "summary": { "total": 4, "by severity": { "critical": 2, "high": 2, "medium": 0, "low": 0 }, "files scanned": 128, "duration seconds": 0.4211, "errors": }, "findings": { "file path": "app/keys.py", "line number": 10, "column number": 19, "algorithm": "RSA-2048", "category": "key-generation", "severity": "critical", "confidence": "high", "rule id": "PQC001", "context hint": null, "migration suggestion": { "recommended algorithm": "ML-KEM-768 CRYSTALS-Kyber …", "nist standard": "FIPS 203 ML-KEM / FIPS 204 ML-DSA ", "docs url": "https://csrc.nist.gov/pubs/fips/203/final" } } } Run pqc-scan on every pull request and surface findings as inline code-scanning annotations. Save this as .github/workflows/pqc-scan.yml : name: pqc-scan on: pull request: push: branches: main permissions: contents: read security-events: write required to upload SARIF to code scanning jobs: pqc-scan: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - name: Run pqc-scan uses: ./ this repo's action; or pin: pqc-scan/pqc-scan@v1 with: path: . severity: high critical | high | medium | low output-sarif: pqc-scan.sarif fail-on-findings: 'false' set 'true' to block the PR on any finding - name: Upload SARIF to GitHub code scanning uses: github/codeql-action/upload-sarif@v3 with: sarif file: pqc-scan.sarif Action inputs | Input | Default | Description | |---|---|---| path | . | File or directory to scan. | severity | medium | Minimum severity to report. | output-sarif | pqc-scan.sarif | Path to write the SARIF report. | fail-on-findings | false | Fail the job exit 1 if any findings are reported. | The action exits 0 when the scan is clean; with fail-on-findings: 'true' the SARIF is still uploaded before the job is failed, so annotations always appear. If you prefer to run the CLI directly without the composite action, the equivalent step is just: - run: pip install -e . && pqc-scan scan . -o sarif -f pqc-scan.sarif -s high Pair it with --changed-only in PR jobs to scan only the diff and keep runs fast. pqc-scan reads a .pqcscan.yml file. It is discovered automatically by walking up from the scanned path, or pointed at explicitly with --config . Generate a starter with pqc-scan init . Full schema: .pqcscan.yml — configuration for pqc-scan exclude: - " /tests/ " - " / .test.py" - " /vendor/ " - " /node modules/ " Minimum severity to report: critical | high | medium | low severity threshold: medium languages: - python - javascript - java - go scan configs: true Scan YAML/JSON/TOML/.conf config files scan dependencies: true Scan dependency manifests requirements.txt, package.json, ... rules: disable: e.g. PQC010 to silence a specific rule output: default format: console console | sarif | cbom | json cbom path: cbom.json Notes: - CLI flags override config values e.g. -s high beats severity threshold . rules.disable takes rule IDs PQC001 … PQC014 , case-insensitive.- Without a config file, the defaults exclude /tests/ , /node modules/ , /.venv/ , /venv/ , /vendor/ , /dist/ , and /build/ the tests glob matches test directories at any depth , and the walker never descends into .git , site-packages , caches, or IDE directories. - A malformed --config file exits with code 2 ; a malformed discovered config prints a warning and falls back to defaults. Every finding ships with concrete, NIST-aligned migration guidance and a before/after code example. The high-level mapping: | Vulnerable today | Migrate to | NIST standard | |---|---|---| | RSA key generation / encryption PQC001/002 | ML-KEM-768 CRYSTALS-Kyber | FIPS 203 | | RSA signatures PQC003 | ML-DSA-65 CRYSTALS-Dilithium | FIPS 204 | | ECDSA / EC keys PQC004 | ML-DSA-65 | FIPS 204 | | ECDH / ECDHE / X25519 PQC005 | ML-KEM-768 | FIPS 203 | | Ed25519 / Ed448 PQC006 | ML-DSA-65 or SLH-DSA | FIPS 204 / 205 | | Diffie-Hellman PQC007 | ML-KEM-768 | FIPS 203 | | DSA PQC008 | ML-DSA-65 | FIPS 204 | | SHA-1 PQC009 | SHA-256 / SHA3-256 | FIPS 180-4 / 202 | | MD5 PQC010 | SHA-256 / SHA3-256 | FIPS 180-4 / 202 | | Weak JWT RS/ES/PS256 PQC011 | HS256 internally; track IETF JOSE for PQC | — | | Weak TLS config PQC012 | TLS 1.3 + hybrid X25519MLKEM768 | FIPS 203 | | DES / 3DES PQC013 | AES-256-GCM | FIPS 197 | Heads-up about liboqs.The Python post-quantum library oqs liboqs-python isnota pure pip install . It wraps the compiledliboqsC library, which must be available first: pip install liboqs builds it from source via CMake, or you install the distro package / build from https://github.com/open-quantum-safe/liboqs . Hash and symmetric replacements SHA-256, AES-256-GCM need no special install — they live in hashlib and the cryptography package. pqc-scan uses two complementary detection strategies: - Code Python, JavaScript/TypeScript, Java, Go : tree-sitter AST analysis. Source is parsed into a concrete syntax tree and the analyzers traverse real nodes — call expressions, imports, dotted attribute access, string and keyword arguments. This is not regex matching: it resolves what is actually being called e.g. rsa.generate private key ... , ec.generate private key ... , so it sees through aliasing and whitespace, reports precise 1-based line/column positions, and avoids matching the same construct inside comments or strings. - Configs and dependencies: pattern-based scanning. TLS/JWT/cipher settings in YAML/JSON/TOML/ .conf , and manifests like requirements.txt and package.json , are matched against curated patterns of quantum-vulnerable algorithms and libraries. Each language analyzer exposes a common contract LANGUAGE , EXTENSIONS , GRAMMAR , analyze ... and emits Finding objects through a single shared factory, so console, SARIF, CBOM, and JSON outputs all stay perfectly consistent. pqc-scan is a static analyzer. It is tuned for high-confidence, low-noise detection, but a few caveats apply: It flags presence, not necessarily exploitable risk. A PQC014 dependency match means a quantum-vulnerable library is declared, not that a vulnerable code path is exercised. Treat findings as an inventory to triage. Dynamic / reflective crypto can be missed. Algorithms chosen at runtime, built from string concatenation, or invoked through heavy indirection may not be resolved by static analysis. Detection is best-effort across libraries. Coverage targets the most common crypto APIs per language; exotic or in-house wrappers may not be recognized. Configuration heuristics are pattern-based and can occasionally over- or under-match unusual config layouts. Tune with rules.disable and exclude . Use --changed-only for fast PR feedback, the full scan for an inventory/CBOM, and the migration guidance attached to each finding as your remediation checklist. Apache-2.0. See the project metadata in pyproject.toml .