Vela — Universal LLM Privacy Gateway

Quantum-resilient PII masking for any app or agent. One npm package, four integration surfaces.

Why Vela beats Rehydra

| | Rehydra | Vela | |---|---|---| | Masked output | <PII type="EMAIL" id="1"/> | [email protected] (FPE) | | Format preserved | No | Yes (length + charset) | | Reversible | Map lookup | Keyed, O(1) memory | | Quantum-resilient | No | ML-KEM-768 + AES-256-GCM | | Multi-tenant | Shared map | Per-tenant key |

Install

npm install vela-privacy

Quick start

const { Vela, QuantumKeyManager } = require('vela-privacy');

// Two parties do ML-KEM-768 key agreement (quantum-resilient)
const alice = QuantumKeyManager.generateKeyPair();
const bob = QuantumKeyManager.generateKeyPair();
const { cipherText, sharedSecret: ss1 } = QuantumKeyManager.encapsulate(bob.publicKey);
const ss2 = QuantumKeyManager.decapsulate(cipherText, bob.secretKey);
const fpeKey = QuantumKeyManager.deriveFpeKey(ss1);

const vela = new Vela({ fpeKey, glossary: ['Neeti', 'JustEase'] });

const masked = vela.mask('Aadhaar 1234 5678 9012, PAN ABCDE1234F');
// "Aadhaar 2602 9025 6010, PAN UDTPKQOYGB"  ← format preserved!

const unmasked = vela.unmask(masked.text, masked);
// "Aadhaar 1234 5678 9012, PAN ABCDE1234F"  ← round-trip

Integration surfaces

| Surface | Use case | |---|---| | Vela.mask/unmask | Direct masking in your code | | maskOpenAiRequest / unmaskOpenAiResponse | Wrap OpenAI SDK calls | | createFetchInterceptor | Zero-code-change fetch interception | | runProxy | Standalone OpenAI-compatible proxy | | Express middleware | For apps that proxy LLM requests |

How it works

1. Detect — regex-based on-device detection of Aadhaar, PAN, GSTIN, emails, phones, case IDs (Indian court formats), plus a configurable glossary.
2. Mask — structured IDs via FF1 FPE (NIST SP 800-38G), soft PII via reversible tokens.
3. Protect — the FPE key is derived from an ML-KEM-768 shared secret, defeating harvest-now-decrypt-later attacks.
4. Restore — de-mask LLM responses using the session's key + token map.

Security model

• ML-KEM-768 (NIST FIPS 203) for key agreement — post-quantum.
• AES-256-GCM protects the FPE key in transit.
• FF1 FPE (NIST SP 800-38G) for format-preserving masking.
• No PII stored in memory maps — FPE is keyed, O(1) memory.
• Per-tenant keys prevent cross-tenant leakage.

Roadmap

• [ ] NER integration (compromise.js / transformers.js) for names/locations
• [ ] Streaming response de-masking (SSE)
• [ ] Key rotation + revocation
• [ ] Audit log of masked fields
• [ ] CLI binary (vela proxy --port 8787)

License

MIT (planned)