ciphertext

End-to-end encryption for your web chats. Messages are encrypted locally, so the site only ever sees ciphertext.

ciphertext adds an independent layer of end-to-end encryption to the web chat and messaging sites you already use. The site stores and transmits only ciphertext — your plaintext never leaves your browser. A small lock button appears on the message box. Click it, choose a recipient, type, and send. ciphertext encrypts locally and injects the ciphertext into the normal input box. Messages from your contacts are decrypted inline. Features • 1:1 and group messages • ECDH P-256 + AES-256-GCM, with hybrid post-quantum encryption (ML-KEM-768) • Add contacts by public key, GPG/OpenPGP armor, or a one-click share link • Decrypts messages inline; unknown senders show a click-to-decrypt overlay • Encrypted, passphrase-protected backups (.ccbackup) • No accounts, no servers, no tracking — keys are stored locally and never leave your device Back up before updating: export a .ccbackup (My Keys → Export backup) before installing a new version. Your identity and contacts live only in your browser, and a new version may change the message format. Compatibility: newer versions read messages from older releases; older clients must update to read new-format messages. Open source under AGPL-3.0. ciphertext is alpha software and has not been independently audited. Do not rely on it where your safety or legal exposure depends on it.