• ☆ Yσɠƚԋσʂ ☆@lemmy.mlOP
    link
    fedilink
    arrow-up
    4
    arrow-down
    1
    ·
    5 hours ago

    You sign up to use Signal using your phone number which is a personally identifying piece of information. Signal clients send messages to the server that routes the messages to their destination. It is not a p2p system where clients talk directly to each other. Therefore, the server must know both the sending and receiving accounts for the messages it routes, and it has the phone numbers associated with this accounts. All these things together make it trivial for the server to know which phone numbers talk to each other.