v133 · web cryptography

End-to-End Encrypted Message

Alice and Bob each generate an X25519 key pair in-browser. They exchange public keys, derive a shared AES-GCM key, and encrypt a message — all using the real SubtleCrypto API. No secret ever leaves the browser.

checking X25519… checking AES-GCM…

1. Keys 2. Exchange 3. Derive 4. Encrypt 5. Decrypt

Alice

Public key (X25519, raw, base64)

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Private key

hidden (CryptoKey object)

Bob

Public key (X25519, raw, base64)

—

Private key

hidden (CryptoKey object)

Key exchange & shared secret derivation

A

Alice derives shared secret using her private key + Bob's public key

Alice's derived AES key (key material hidden by browser)

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B

Bob derives shared secret using his private key + Alice's public key

Bob's derived AES key

—

Encrypt a message (Alice → Bob)

Ciphertext (base64)

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IV (base64)

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Decrypt (Bob receives)

Decrypted plaintext

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Event log

Waiting for key generation…