Signal is the world’s most widely used truly private messaging app, and our cryptographic technologies provide extra layers of privacy beyond the Signal app itself. Since launching in 2013, the Signal Protocol—our end-to-end encryption technology—has become the de facto standard for private commu...
Not necessarily.
Signal has people who are experts in their field. They engineer solutions that don’t exist anywhere else in the market to ensure they have as little information on you as possible while keeping you secure [0]. This in turn means high compensation + benefits. You don’t want to be paying your key developers peanuts as that makes them liable to taking bribes from adversaries to “oops” a security vulnerability in the service. In addition, the higher compensation is a great way to mitigate losing talent to private organizations who can afford it.
[0] Signal has engineered the following technologies that all work to ensure your privacy and security:
At least the private contact discovery is not very private:
Phone numbers are so not-sparse that there even was a game to text your “number neighbor”. I can probably build a pretty effective rainbow table for this with my current hardware.