Keychat

The sender transmits a message marked with Bitcoin ecash to a Nostr relay. The Nostr relay collects the Bitcoin ecash and then forwards the message to the recipient. Unlike centralized postal systems, Keychat can utilize multiple Bitcoin ecash issuers and Nostr relays, each maintained by different operators. Keychat employs the Signal protocol to ensure message encryption and metadata privacy. Opening an envelope can easily expose the contents of a letter. Keychat messages are end-to-end encrypted via the Signal protocol, generating a unique encryption key for each message. Only the sender and recipient can decrypt the messages. The addresses of both parties on the envelope are traceable. Theoretically, this issue could be resolved if they changed addresses daily. Therefore, Keychat reuses the Signal protocol to update the sending and receiving addresses for nearly every message. No registration is required. As a chat client based on the Nostr protocol, you only need to create a Nostr account to log in—no phone number, email, or any other registration method is necessary. You must safeguard your nsec key, as it grants you control over your data. Additionally, your Nostr account is compatible with other Nostr clients.

Keychat is a super app designed for Bitcoin users, integrating self-sovereign identity, Bitcoin cash wallets, secure chat, and rich mini-apps. It uses Bitcoin cash and the Nostr protocol for messaging, with the Signal protocol ensuring end-to-end encryption and metadata privacy.