The encryption a quantum computer cannot break — running on this phone, step by step. ML-KEM-768, the NIST standard since 2024, implemented from the text of the standard.
Alice makes a key pair. Bob locks a fresh secret to her public key. Alice unlocks it with her private key. Then flip one byte of what Bob sent and watch it fail silently.
The shared secret becomes an AES-256 key. Type anything; it is encrypted on Bob's side and decrypted on Alice's.
| Scheme | Public key | Ciphertext | Quantum computer |
|---|---|---|---|
| RSA-2048 | 256 B | 256 B | breaks it (Shor, 1994) |
| X25519 (elliptic curve) | 32 B | 32 B | breaks it (Shor, 1994) |
| ML-KEM-768 | 1184 B | 1088 B | no known attack |
Bigger keys are the price. Chrome, Firefox and Cloudflare already pair X25519 with ML-KEM-768 in TLS — so the connection to this very page may have used it.
RSA rests on factoring, elliptic curves on discrete logs — a quantum computer solves both with Shor's algorithm. ML-KEM rests on a different problem: given a matrix A and A·s + e with small noise e, find s. No quantum algorithm is known to do that faster than a classical one.
⋰FIPS 203, published by NIST in August 2024, after a six-year open competition. This page implements it line by line: Keccak, arithmetic in Z₃₃₂₉, the number-theoretic transform, sampling, compression, K-PKE, the KEM with implicit rejection.
◫Six deterministic seeds through this code and through an independent implementation: public keys, private keys, ciphertexts and shared secrets agree byte for byte. SHA-3 and SHAKE match the standard's test vectors. A full exchange takes about 50 ms here.
↗What this is not Demonstration code, so you can see every step. It has no constant-time guarantees and no audit. For anything real, use a vetted library or the browser's own crypto once it ships ML-KEM.
Sizes: public key 1184 bytes, private key 2400, ciphertext 1088, shared secret 32 — exactly as FIPS 203 specifies for ML-KEM-768.
No server, no request after the page is open. Keys are made here and die with the tab.