You can deny the Signal app the address book permission and it still works.
Signal contact discovery is also the most privacy preserving approach available anywhere, using only the partial hash of their phone number. You don't have to share your contacts -- but yes, your contacts may share their truncated hash list, and hence discover that your number is tied to a Signal identity, but it is on their phone that the number maps to a name, not in any network traffic or on a Signal server.
We're really not getting any better solutions until secure MPC becomes more practical.
Signal contact discovery is also the most privacy preserving approach available anywhere, using only the partial hash of their phone number. You don't have to share your contacts -- but yes, your contacts may share their truncated hash list, and hence discover that your number is tied to a Signal identity, but it is on their phone that the number maps to a name, not in any network traffic or on a Signal server.
We're really not getting any better solutions until secure MPC becomes more practical.
https://www.howtogeek.com/708651/can-you-use-signal-without-...
https://signal.org/blog/private-contact-discovery/