Encryption is coming to RCS, protecting Android and iPhone

Now that Apple supports Rich Communication Services (RCS) messages on iPhones running iOS 18, the GSM Association (GSMA) has promised end-to-end encryption (E2EE) is coming to the standard, a move that should better protect communications between iPhone and Android devices.

The GSMA, which maintains the standard, is working to implement E2EE but hasn’t committed to a time scale. It announced the plans as it marked the launch of RCS support on the iPhone.

E2EE will be ‘next major milestone’ for RCS

“While this is a major milestone, it is just the beginning,” the GSMA said in a statement. “The next major milestone is for the RCS Universal Profile to add important user protections such as interoperable end-to-end encryption. This will be the first deployment of standardized, interoperable messaging encryption between different computing platforms, addressing significant technical challenges such as key federation and cryptographically-enforced group membership. Additionally, users will benefit from stronger protections from scam, fraud, and other security threats.”

RCS Universal Profile is an industry-agreed set of features and technologies the GSMA has standardized so RCS can be widely deployed in products and services. The most recent version, RCS Universal Profile 2.7, introduced support for more advanced messaging features, such as reactions, editing of sent messages, and improved message indicators.

Apple now supports RCS on iPhone

Apple has now adopted RCS within iOS 18, replacing the long-in-the-tooth SMS system for texts to Android devices. Messages between the platforms are much improved as a result — many users were annoyed that they couldn’t share high-resolution images, for example. 

However, the lack of E2EE is a glaring hole in messaging security; it means enterprise users will likely employ other messaging services for critical information. Apple’s own message system does support E2EE, but not when sharing with an Android device — hence, the colored bubbles to show you when a message is secure. You will know when you’re in an RCS chat with an Android user because you’ll see a small grey label that says RCS Message in the text field.

Other significant benefits

The GSMA promise of encryption in RCS is a welcome one. It will prevent carriers, messaging services, or other third parties with access to these communications from viewing the content of the texts you share or sharing that information for any reason.

Encryption on messages between platforms also promises other benefits, as noted last year by Caitlin Seeley George at Fight for the Future: “This move makes it possible for cross-platform messages to be end-to-end encrypted — a security feature that would protect a whole host of vulnerable groups, including pregnant people, LBGTQ+ people, activists, immigrants, and journalists.”

It is possible that Apple’s decision to introduce support for RCS might have helped it avoid its messaging service being declared a ‘Gatekeeper’ service under the EU’s DMA. 

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