Rich Communication Services, or RCS, is a messaging technology intended to replace traditional SMS and MMS. It allows encrypted communication between devices and includes features such as read receipts, multimedia messaging, and typing indicators. RCS became the default messaging platform for Android in 2019, and Apple has recently introduced support for it in iOS 18’s beta build.
Even though RCS is an industry standard, the current feature set utilized by most RCS apps (Universal Profile 2.4) does not provide end-to-end encryption (E2EE); instead, data is encrypted during transit using TLS and IPsec by default. Google had previously addressed this issue by embedding its own E2EE implementation in Google Messages, but with Apple adopting RCS and third-party Android SMS apps expecting to add support, a common encryption protocol is still required.
To meet this need, Google announced support for Messaging Layer Security (MLS) last year, giving the new standard an early boost. The Internet Engineering Task Force (IETF) developed MLS, an upgraded protocol. It ensures that communication between apps and platforms is encrypted in both one-on-one and group conversations.
Assemble Debug, a code hunter, has now uncovered strings and flags relating to Messaging Layer Security (MLS) in the Google Messages app, implying that it will be added soon. The functionality is currently in development, and it’s unclear how it will be integrated into Google Messages.
Google Messages prepares support for Messaging Layer Security (MLS)
Importantly, the strings hint to Google’s aim to make MLS the default security layer for messaging. This is an important step toward a future in which several messaging apps use the same encryption standard, potentially paving the road for safe chatting between services – assuming others adopt MLS, of course. At the absolute least, by making MLS the default, Google would portray Messages as a pioneer in the push toward an interoperable, yet encrypted future.
Google’s acceptance of MLS may also have consequences for Apple’s upcoming inclusion of RCS into its Messages app, which houses iMessage. Currently, the company’s version of RCS in iOS 18 Beta 2 does not support E2EE in group conversations. While Google Messages supports E2EE in group and solo chats, it does so using a customized version of the RCS Universal Profile standard. It seems unlikely that Apple will include this proprietary encryption in its Messages app, therefore an industry standard like MLS may fill the void.
RCS has been Google’s favorite communications project since it abandoned the practice of developing a separate messaging app for every imaginable use-case, and its efforts appear to be paying off. With Apple joining the fold and a new encryption standard that could lower the entrance hurdle for other firms to follow suit, the future of RCS messaging seems bright after nearly a decade of Google’s support.
