zlacker

I would disagree with the "that's a detail" statement. Properly salted hashes make building a social network graph much more difficult. It's only relatively easy to brute-force a single number.

>>jwr+(OP)
I don’t think they are salted. When someone joins signal they are compared to your hashes. That is how you get notified that one of your contacts have joined signal.

If they were all individually salted, there would be no way to compare against new joiners.