Discord Age Encryption av Sensei

A MV3 browser extension that adds end-to-end post-quantum age encryption to Discord.
Messages are encrypted on your device before being sent — Discord's servers only see ciphertext.

Features

• End-to-end encryption – Messages are encrypted on the sender’s device and decrypted only on recipients’ devices.
• Digital signatures – Messages are signed using public-key cryptography, providing authenticity and non-repudiation.
• Passphrase protection – Encryption keys are unlocked with your passphrase for each session.
• Post-quantum cryptography – Uses ML-KEM-768×X25519 hybrid key encapsulation for quantum-resistant key exchange.
• Memory-safe algorithms – Rust-based implementations of ML-DSA-87, Argon2id, XChaCha20-Poly1305, and SHAKE256 compiled to WebAssembly via rustcrypto-wasm.

Cryptography

Encryption uses age (ML-KEM-768×X25519 hybrid key agreement + ChaCha20-Poly1305), a modern and well-audited encryption format. Each message is also signed with an ML-DSA-87 signature, which guarantees that a message could only have been sent by the person who owns that keypair – any tampering or forgery is flagged immediately.

Your data is stored encrypted at rest on your device using Argon2id + XChaCha20-Poly1305. It is never uploaded anywhere.

Message format

Encrypted messages are sent as Discord file attachments (.age files). Each file begins with a version byte, followed by an ML-DSA-87 signature, a sender public-key hint, and the age ciphertext. The signature input binds a channelId (and serverId for servers) to prevent cross-channel replay. Messages are encrypted to all recipients and the sender, so the relevant parties can read the conversation.

Key fingerprints

Each contact's public key is displayed as a SHAKE256 (64-byte output) fingerprint. You can verify a contact's key out-of-band by comparing fingerprints with them directly if you wish.

Limitations

• No forward secrecy. If your private key is ever compromised, past messages encrypted to it could be read. Keep your passphrase strong and your private key safe.

Troubleshooting

See TROUBLESHOOTING.md.

Getting started

First time setup

1. Click the extension icon in your toolbar;
2. Choose a strong passphrase (at least 20 characters, mixed case, numbers, and symbols);
3. Click Generate keypair – your keys are created and stored locally;
4. Click My public key and copy it to share with your contact.

Adding a recipient

1. Open a contact, group or server in Discord;
2. Click + Add in the extension;
3. Fill in the required details;
4. Click Save once done.

All sides need to have added each other before encrypted messaging works correctly.

Sending messages

Once a given recipient is added and enabled, just type your message and press Enter – the extension intercepts and encrypts it before sending. Hit enter again to confirm.

Received encrypted messages are decrypted and shown inline with a lock badge.

Third-Party Notices

See NOTICES.md for the third-party notices.

Not affiliated with Discord Inc. Research project, use at your own risk.