You can now use RCS between iOS and Android, but this critical feature is still MIA

This week has been a big one for mobile connectivity, as with the release of iOS 18, Apple users en masse are beginning to communicate via RCS, the modern messaging standard intent on creating a feature-rich, level playing field for everyone. For Android users who have long felt like second-class citizens in the eyes of their blue-bubble friends and family, this is one advancement that’s been a long time coming (even if those green bubbles aren’t going anywhere). But for as momentous as crossing this threshold has been, there’s still lots of work to be done, and one of the most important messaging features around still needs to make the evolution to cross-platform support.

If you’re on Android and message another Android user over RCS, Google is going to secure your chat with end-to-end encryption (E2EE), so that not even your carrier can read what you’re sending. That works for group chats, just as well as one-on-one conversations, but Google’s implementation is a bit of a custom job that exists on top of vanilla RCS — the RCS Universal Profile.

In order to get E2EE working cross-platform between Android and iOS, we’re going to need some support for E2EE baked into the Universal Profile — and that’s just what the GSMA, the organization behind RCS, says it’s working towards (via 9to5Google). Google General Manager Elmar Weber shares some words of support on LinkedIn, posting:

…we have been working with the broader ecosystem to bring cross-platform E2EE to RCS chats as soon as possible. Google is committed to providing a secure and private messaging experience for users, and we remain dedicated to making E2EE standard for all RCS users regardless of the platform.

With the GSMA and Google both behind this push, our next question might be how this new support could be likely to take shape. We’ve already been following Google’s interest in Messaging Layer Security (MLS), a protocol that doesn’t just support E2EE between individuals, but can secure group chats just as well.

Messages shows signs of development work towards supporting MLS in this manner, and while we’d say that looks like a very solid possibility for how E2EE in the Universal Profile could be realized, right now neither the GSMA nor anyone we’ve seen from Google is saying anything very specific about those plans.

In all fairness, it’s not like we’re taking a step back here, and messaging between iOS and Android users over traditional SMS was never E2EE protected in the first place. But user expectations have also come a long way from the days we were all texting with T9, so hopefully it won’t be overly long before we see RCS add this highly requested capability.