# ML-KEM (Post-Quantum)
URL: /docs/experiments/ml-kem
> Post-quantum ML-KEM-768 (Kyber) key encapsulation with Web Crypto at the edge - PQC demo for quantum-resistant key exchange
Tags: edge, crypto, post-quantum, ml-kem, kyber, pqc, web-crypto, security
Markdown: /llms.mdx/experiments/ml-kem/content.md
**ML-KEM** (formerly **Kyber**) is NIST's post-quantum key encapsulation standard. This Worker demonstrates **ML-KEM-768** with the Web Crypto API on Cloudflare Workers: generate a key pair, encapsulate a shared secret, and decapsulate to verify - a pasteable PQC reference for quantum-resistant key exchange at the edge.
## API Reference [#api-reference]
### `GET /keygen` [#get-keygen]
Generate an ML-KEM-768 key pair, encapsulate to a ciphertext, and decapsulate to verify that the shared secrets match.
**Parameters:** None
**Example request**
```bash
curl https://ml-kem.example.workers.dev/keygen
```
**Example response**
```json
{
"algorithm": "ML-KEM-768",
"publicKey": "a1b2c3d4...",
"ciphertext": "e5f6g7h8...",
"encapsulatedSecret": "i9j0k1l2...",
"decapsulatedSecret": "i9j0k1l2...",
"secretsMatch": true,
"publicKeyLength": 1184,
"ciphertextLength": 1088,
"sharedSecretLength": 32
}
```
**Fields**
* **`algorithm`** `string` - The ML-KEM variant used (ML-KEM-768)
* **`publicKey`** `string` - Hex-encoded public key
* **`ciphertext`** `string` - Hex-encoded ciphertext from encapsulation
* **`encapsulatedSecret`** `string` - Truncated hex-encoded shared secret (first 32 chars + "...")
* **`decapsulatedSecret`** `string` - Truncated hex-encoded shared secret from decapsulation
* **`secretsMatch`** `boolean` - `true` when encapsulated and decapsulated secrets match
* **`publicKeyLength`** `number` - Public key size in bytes (1184 for ML-KEM-768)
* **`ciphertextLength`** `number` - Ciphertext size in bytes (1088 for ML-KEM-768)
* **`sharedSecretLength`** `number` - Shared secret size in bytes (32)
## Use Cases [#use-cases]
* Demonstrating post-quantum cryptography at the edge
* Testing ML-KEM-768 implementation for migration planning
* Building quantum-resistant key exchange demos
* Educational exploration of NIST post-quantum standards
## Limitations [#limitations]
* Uses the `webcrypto_modern_algorithms` compatibility flag (may not be available in all environments)
* Generates a fresh key pair on every request (stateless demo)
* Shared secrets are truncated in response for readability
* No persistent storage or key management
## Use in your project [#use-in-your-project]
## Deployment [#deployment]
### Deploy to Cloudflare Workers [#deploy-to-cloudflare-workers]
[](https://deploy.workers.cloudflare.com/?url=https://github.com/shrinathsnayak/cloudflare-experiments/tree/main/apps/experiments/ml-kem)
The Worker is live once deployment succeeds.
### Test the endpoint [#test-the-endpoint]
```bash
curl https://ml-kem.your-subdomain.workers.dev/keygen
```
You should see a JSON response with `secretsMatch: true`.
## Local Development [#local-development]
```bash
cd apps/experiments/ml-kem
npm install
npm run dev
```
The Worker runs at `http://localhost:8787`.
**Test locally**
```bash
curl http://localhost:8787/keygen
```
## Configuration [#configuration]
### Compatibility flags [#compatibility-flags]
This experiment requires the `webcrypto_modern_algorithms` flag in `wrangler.json`:
```json
{
"compatibility_flags": ["webcrypto_modern_algorithms"]
}
```
No bindings or secrets required.
## Cloudflare Features Used [#cloudflare-features-used]
* [Workers](https://developers.cloudflare.com/workers/) - Edge compute platform
* [Web Crypto API](https://developers.cloudflare.com/workers/runtime-apis/web-crypto/) - Cryptographic operations at the edge
* ML-KEM-768 post-quantum key encapsulation (via `webcrypto_modern_algorithms` flag)
## Next Steps [#next-steps]