bitchat

Bitchat is a fully open-source, decentralized messaging app developed by Jack Dorsey (Block, Inc.) that operates over Bluetooth Low Energy (BLE) mesh networks, enabling encrypted peer-to-peer communication without internet, servers, or phone numbers. It features multi-hop relaying reaching over 300 m, end-to-end encryption (Curve25519/AES‑GCM), password-protected channels, offline message storage and forwarding, cover traffic, and emergency data wipe options all released under the public domain Unlicense on GitHub. Notable open-source alternatives include Briar, a GPL‑3 licensed mesh messenger that supports encrypted chat via Bluetooth, Wi‑Fi, or Tor without internet reliance and Bridgefy, a mesh-capable SDK/app formerly popular in protest environments though with noted security limitation

Features

• Decentralized Mesh Network: Automatic peer discovery and multi-hop message relay over Bluetooth LE
• End-to-End Encryption: X25519 key exchange + AES-256-GCM for private messages and channels
• Channel-Based Chats: Topic-based group messaging with optional password protection
• Store & Forward: Messages cached for offline peers and delivered when they reconnect
• Privacy First: No accounts, no phone numbers, no persistent identifiers
• IRC-Style Commands: Familiar /join, /msg, /who style interface
• Message Retention: Optional channel-wide message saving controlled by channel owners
• Universal App: Native support for iOS and macOS
• Cover Traffic: Timing obfuscation and dummy messages for enhanced privacy
• Emergency Wipe: Triple-tap to instantly clear all data
• Performance Optimizations: LZ4 message compression, adaptive battery modes, and optimized networking

Basic Commands

• /j #channel - Join or create a channel
• /m @name message - Send a private message
• /w - List online users
• /channels - Show all discovered channels
• /block @name - Block a peer from messaging you
• /block - List all blocked peers
• /unblock @name - Unblock a peer
• /clear - Clear chat messages
• /pass [password] - Set/change channel password (owner only)
• /transfer @name - Transfer channel ownership