I have a lot of friends and family that use SMS/RCS and I can’t get them all to use Signal.
I have the option to send SMS from a simple FOSS SMS app, and then we can communicate back and forth.
I’ve heard something about RCS getting E2EE and find that appealing.
What is the future of RCS? What are my options, and should I just stick with SMS?
Edit: Stick with SMS when I have to, and use Signal etc when possible ofc.
With RCS, you’ve got multiple components to deal with. There’s the clients, but there’s also the servers. RCS is tied to your phone number and IMEI. This means that it’s the telcos who route the messages.
But unlike SMS, where the line level protocol had a back channel designed to transmit these short messages, RCS goes over LTE, which means it needs a network server to send and receive these short messages (more like email).
This means that someone needs to set up and manage the servers for each telco, and route the messages from there to the related numbers.
In the US, the vast majority of ISPs have hired a third party to handle this for them. That third party is Google.
So while the message contents are e2e encrypted, the trunking information and encrypted data can all flow through Google’s servers, even if both recipients are using iMessage, if they’re communicating by RCS instead of iMessage protocol and their telco uses Google for RCS trunking.