| Lets play here for a bit.. Whats App (a currently end to end encrypted message system) will have to be able to send messages to other messaging platforms. Complications. 1. The api's of these systems (as well as the user authentication) will have to become public. - That's really a problem for these companies, if they don't have a SingleSignOn solution. - That's not really a problem if they use a third party SingleSignOn solution (Many use facebook or google) 2. Text that gets sent to "the other platforms" will have to be decrypted inside those platforms. - This is a problem because they'll have to use the same (IP protected) algorithm. OR. Whats app can decrypt the message in the cloud, and send it decrypted. Thus breaking their entire reason for being, and killing E2E coms. BOTH these complexities open the users up for security violations. For a group that want to allow its people to own their data, and not be tracked by cookies, this seems like a huge step into insecure coms. |
Allow users to bring their own client. Depending on particulars in resulting regulation, could also mean federation (where S2S means passing on encrypted messages, the content of which is of course encrypted).
Maybe not everyone here are aware that WhatsApp, FB Messenger and Google Talk/Hangouts/whatever were all speaking XMPP before they eventually went closed. There was a time when you could connect to all of them from the same client speaking the same protocol, and talk to people on different servers. WhatsApp's server side started as a fork of ejabberd.
The most straightforward way (assuming non-malicious compliance, which TBF may be far-fetched) for this would probably be XMPP with a well-defined set of extensions. This would not require compromising user security, nor would it require SSO.