It’s unfortunate that you react like this. I don’t claim to be an expert, never have. I’ve only been asking for evidence, but all we get to are assumptions and they all seem to stem from the fact that allegedly the CIA has indirectly funded Signal (I’m not disputing nor validating it).
The concern is valid, and it has caused a lot of distrust in many companies due to the Snowden leaks, but that distrust is founded in the leaks. But so far there is no evidence that Signal is part of any of it. And given the continued endorsement by security experts, I’m inclined in trusting them.
From what I understand, sealed sender is implemented on the client side. And that’s what’s in the github repo.