Rich Communication Services (RCS) is a messaging protocol designed to upgrade traditional SMS and MMS. It enables features like encrypted communication, read receipts, multimedia messaging, and typing indicators. Since becoming Android’s primary texting platform in 2019, RCS has been adopted by Apple with the introduction of iOS 18 in its latest beta build.
Despite RCS being an industry standard, the commonly used version (Universal Profile 2.4) lacks end-to-end encryption (E2EE) by default. Instead, it relies on transport encryption via TLS and IPsec. Google has addressed this limitation by implementing its own E2EE in Google Messages, while Apple and third-party Android SMS apps have yet to add support for a standardized encryption protocol.
Google is now pushing for Messaging Layer Security (MLS), a protocol developed by the Internet Engineering Task Force (IETF), to standardize encrypted communication across apps and platforms. MLS provides encryption for both one-on-one and group chats, aiming to enhance the security and interoperability of messaging services.
Recent discoveries by code analyst Assemble Debug indicate that Google Messages is preparing to support MLS. The integration details are still under development, but Google intends to make MLS the default security layer. This could lead to multiple messaging apps adopting the same encryption standard, facilitating secure communication across different services.
Google’s move towards MLS aligns with Apple’s recent support for RCS. However, Apple’s implementation in iOS 18 Beta 2 does not yet include E2EE in group chats. While Google Messages currently supports E2EE in both individual and group conversations using a proprietary extension to the RCS standard, it is unlikely that Apple will adopt this proprietary encryption. Instead, an industry-wide standard like MLS could provide a unified solution for secure messaging across platforms.
Google intends to make MLS the default security layer |
Google’s ongoing investment in RCS is showing promising results, especially with Apple’s adoption and the potential for MLS to become a widely accepted encryption standard. This development could ease the integration of other companies into the RCS ecosystem, enhancing the security and usability of messaging services.