There is a major issue with Signal: Your account is tied to your phone number.
This makes these apps really easy to use, since there are no usernames or passwords to deal with. It also makes it easy to discover other app users; if someone is a contact in your phone and has the app installed, you can send them encrypted texts with no further effort. But it also means that if you want people to be able to send you messages securely, you need to hand out your phone number. This puts people who interact with the public in an awkward bind: Is the ability for strangers to contact you securely worth publishing your private phone number?
In this article I explain how to create a second Signal number that is safe to publish on your Twitter bio and business cards, so strangers have an easy way to contact you securely, while your primary phone number remains private. I explain how to obtain a second phone number, how to register it with the Signal server, and how to configure it to use Signal Desktop — even if you’re already using Signal Desktop with your private phone number.