I've been a user and close follower of all things a Signal for over a decade. This person's blog is a little more than a hit piece, and makes wild exaggerated accusations which can't be proven. First and foremost of which is that Signal had any CIA funding. That's just absurd. Way back and it's early days Signal got an award from the "open technology fund" which is government money, but the government has no control over who gets the award. That money isn't even relevant anymore, Signal gets its funding from a donation from Brian Acton and donations from users.
Discussion
Thanks for the explanation.
Ok but no technology can be closed source and still claim to not be beholden to the CIA, because the claim cannot be proven.
Uh...yeah...except Signal is very proudly open source, always has been.
Ok, can it be used without a phone number?
No not at the moment. Reason being is a phone number was necessary from the beginning when it was Text Secure and used SMS as a means to send e2ee messages. Using phone numbers as identifiers for your existing social graph was necessary for onboarding.
However, usernames are in the works and expected to be implemented in early 2024. Once that is complete a phone number will only be necessary for registration, and no one not even Signal will be able to associate a phone number with a username unless you want them to.
Retaining usernames for registration is a good idea because it prevents would be spammers from just creating a near infinite number of accounts.
Oh and if you want you don't have to register with your own phone number, as long as you can receive a text or voice message to whatever number you give during registration you'll be fine. I've even heard of people registering using a payphone.