[f38zf5vdt]

Technically we also trust Signal not to push a signed update to their software that exfiltrates our keys. Whether or not Meta is doing E2EE should be clear from snooping their protocol or reverse engineering the software.

[_Algernon_]

Nothing is stopping you from auditing the code and building the client software yourself: https://github.com/signalapp

You don't even have that option with closed source software.