Depends, who do you want to shield what information from? Signal knows all of their users’ phone numbers. You can hide it from other Signal users. All depends on your threat model.
How exactly is it hashed? There aren’t that many possible phone numbers, so it might be viable to just try every valid number until you find one that matches
Right, then Signal might not be the best option. The NSA can easily track who’s using Signal, and possibly do some traffic correlation to reveal who’s talking to who.
But to state that there is no privacy on Signal at all is a bit of a stretch.
Depends, who do you want to shield what information from? Signal knows all of their users’ phone numbers. You can hide it from other Signal users. All depends on your threat model.
Only the hash of your phone number.
How exactly is it hashed? There aren’t that many possible phone numbers, so it might be viable to just try every valid number until you find one that matches
Here’s what Signal says: https://signal.org/blog/contact-discovery/
The NSA
Right, then Signal might not be the best option. The NSA can easily track who’s using Signal, and possibly do some traffic correlation to reveal who’s talking to who.
But to state that there is no privacy on Signal at all is a bit of a stretch.