Please also take a look at nostr:nprofile1qqsth7fr42fyvpjl3rzqclvm7cwves8l8l8lqedgevhlfnamvgyg78spz3mhxue69uhhyetvv9ujuerpd46hxtnfduq3qamnwvaz7tmwdaehgu3wwa5kuegpz4mhxue69uhk2er9dchxummnw3ezumrpdejqj9swg4. It uses Signal's end-to-end encryption and runs with the Nostr protocol. You can use multiple keys for different chats.