VaultChat is a peer-to-peer encrypted messenger built on the Nostr protocol. Unlike Signal or WhatsApp, it requires no phone number, no email, and no account registration. Your identity is a cryptographic keypair generated locally on your device. Key features: - NIP-44 v2 end-to-end encryption - QR code contact sharing - Encrypted file transfer - Encrypted backup and restore - PIN + biometric lock - Multi-relay support - Fully open source No central server. No metadata. No tracking.