Signal is almost entirely open source but not interoperable
Natanael
The message transit encryption is on but backups are unencrypted by default, which makes it quite pointless
The RCS e2e extension is client controlled, the client app knows if it's active
However access to each carrier gateway is very guarded ...
They haven't really. What they really should do is run their own RCS server and federate and support the e2e extension, but they don't want to.
The most annoying part is that the imessage encryption protocol is so far behind state of art (same underlying encryption protocol with small RSA keys and no deniability since ~2011 when Signal has been around since 2010 with a better protocol). Meanwhile Google based their encryption extension on the Signal production. It would be a solid security improvement if Apple adopted it.
Google's encryption extension is published so anybody could implement it (if you already have enough access to create your own client, like Samsung)
FYI RCS with the e2e encryption extension enabled is harder to snoop on even for Google than it is to snoop on infamously insecure SMS
RCS has an e2e encryption extension (created by Google)
Technically cables are part double sided (USB3 wires, grounding) and part single sided (power, USB2), while ports should be double sided.
It's not entirely wrong, public transit is better