Signal contact ≠ Phone contact address book. By disabling Signal’s access to phone contact address book, Signal server would not have a hash value of each and

Signal contact ≠ Phone contact address book. By disabling Signal’s access to phone contact address book, Signal server would not have a hash value of each and every (10,000+) phone numbers in your phone’s contact address book. This disabling comes with small costs of: - being notified that someone in your phone’s contact address book has just recently signed up with Signal. (Pop your finger from your mouth) - of ease of NEW lookups of a friend using your expansive 10,000+ contact address book that your phone maintains. Ummm, your focus is the secured messaging with just the targeted friends of yours, and not one of your crazed ex-girlfriend nor deranged boss. You still have a separate but more secured form of a contact address book maintained by Signal (and yes, remote Signal server has a hash value of these smaller but limited set of Signal-capable phone numbers of your friends). The key thing is no one else can see the content of your messaging … over Signal … except who you converse with … by Signal app, unless your phone ends up in the hand of a digital forensic guy before you did the steps of doing “Settings->Account->Delete Account”. On a separate topic, you should refrain from using Avatar and discourage your friends from doing so. That’s an out-of-band lookup that is available for nation-state or hacker to profile further with.