Recently discovered this. Molly supports link with existing device just like on signal desktop. It even has benefit of getting entire chat history unlike signal desktop. Just restore the signal backup file during setup and then click link with existing device. Then scan with you primary phone. Beauty of open source. Molly: https://molly.im/
The signal source code is open source, it is hard to prove that the servers are running the source code that’s published, and we know they have admitted to having source code they don’t publish for anti-spam purposes.
But you could take the signal server source code and stand up your own signal servers today.
impossible*
The Signal protocol is built in a way where you don’t have to trust the server. The servers could be run by the NSA, it wouldn’t matter. Especially now that the Signal protocol uses post-quantum cryptography.
And how do I tell may client to use only a specific server?
If your going to run a independent signal server cluster, you will also need to modify the client applications to connect to your cluster.
You probably would find the molly developers happy to accept a push request to have some configurable backend selection.
Session demonstrates this is possible.
If yo run your signal server does it come with the new quantum E2EE?
Good question, check with the signal github
I don’t know man, seems to me XMPP is more secure (unless you trust Signal) and simple to use because you have to jump less hoops
By all means, go with the platform you like better!
https://www.privacyguides.org/en/real-time-communication/
Are all perfectly acceptable options
AFAIK it’s entirely done in the client. The server doesn’t perform any encryption/decryption other than TLS.