DisCrypt - End-to-End Encryption for Discord

Secure peer-to-peer messaging on Discord using client-side encryption. Messages and files remain encrypted end-to-end, even if your Discord account is compromised.

How It Works

1. Add a peer by their Channel ID (DM channel) and public keys
2. Messages auto-encrypt on send, auto-decrypt on receive, message edition is well handled
3. Only you and the intended recipient can read your messages
4. Encryption verified with color coding (blue = sent, green = received)

Features

• End-to-end encryption using X25519 ECDH + XSalsa20-Poly1305 (TweetNaCl)
• Automatic message encryption/decryption
• Encrypted file attachments with Ed25519 signature verification
• Message editing support
• Reply handling for encrypted messages
• Peer management UI with key storage
• Works in DMs and group channels

Security Model

Threat Model: Protects against message interception if your account is compromised.

Does NOT protect against:

• Private key compromise (if your computer is compromised)
• Man-in-the-middle attacks during key exchange (manually exchange keys via secure channel)
• Message metadata (timestamps, message count, presence)

Implementation Details:

• Private keys stored in browser localStorage only
• Uses NaCl.box (X25519 ECDH) for asymmetric encryption
• Ed25519 signatures for file authenticity verification
• Sender/recipient public keys included in message format for verification

Limitations

• No forward secrecy (compromise of keypair compromises all messages)
• No built-in key exchange protocol (manual key sharing required)
• Private keys stored in plaintext in localStorage
• File upload MIME type spoofing (.png wrapper) for CORS bypass

TODO

• GUI improvements
• Message editing
• File encryption/decryption
• Reply handling
• Message authenticity verification (sender signature)
• Forward secrecy (keypair rotation)
• Key import/export with password protection
• Code refactor for maintainability
• Link preview support
• Better media handling after decryption