Post-quantum cryptography isn't a slide deck. It's running on this page. Generate real ML-KEM and ML-DSA keys, swap secrets, forge a signature and watch it fail, then see how hash functions scramble input.
Alice and Bob want a shared secret that eavesdroppers can't recover, even with a future quantum computer. Classic key exchange (X25519, RSA) falls to Shor's algorithm. ML-KEM (formerly Kyber) is based on lattice problems that no known quantum algorithm solves efficiently. It's the NIST standard now shipping in TLS, Signal, and SSH.
She publishes the public key. The secret key never leaves her device.
Using only Alice's public key, Bob makes a fresh 32-byte shared secret and a ciphertext that wraps it. He sends Alice the ciphertext.
With her secret key, Alice opens the ciphertext and recovers the same 32 bytes. An eavesdropper who saw the public key and ciphertext gets nothing.
Post-quantum security costs bytes. Here's ML-KEM-768 next to classic X25519 (a fresh X25519 exchange also ran in your browser just now).
Why we deploy both: production systems use a hybrid (X25519 + ML-KEM, as in Chrome's and Cloudflare's TLS). An attacker has to break both. You get quantum resistance without betting everything on a young algorithm.
ML-DSA (formerly Dilithium) is the post-quantum replacement for RSA and ECDSA signatures. Sign a message, then flip a single bit of the signature and watch verification fail.
Type anything. Each hash function turns it into a fixed-size fingerprint, and the smallest change gives a completely different one. Outputs update as you type.
We flip one bit of your input's last character and hash both versions. A good hash changes about half of its 256 output bits. Gold squares are the bits that flipped.
Fast hashes are wrong for passwords because attackers can try billions per second. Argon2id is deliberately slow and memory-hard, so each guess costs real RAM and time. It hashes the input above in a background thread, in pure JavaScript (native code is several times faster).
We design hybrid post-quantum migrations, key management, and audited crypto for web, Web3, and backend systems.