GSMA on Friday announced new specifications for Rich Communication Services (RCS) that bring end-to-end encryption (E2EE) using the Messaging Layer Security (MLS) protocol.
Tom Van Pelt, Technical Director at GSMA, said these updates explain how MLS works within RCS to keep messages, files, and other content private and secure as they move between users’ devices. He added that this makes RCS the first major messaging platform to offer interoperable E2EE across different providers’ apps.
Van Pelt highlighted that, alongside features like SIM-based authentication, E2EE boosts privacy and protects users from scams, fraud, and other threats. He noted that these security upgrades are central to the new RCS Universal Profile 3.0 release. This version also improves business messaging with a richer deep link format, adds better audio codecs, and simplifies managing subscriptions to business senders.
The announcement detailed several new RCS specifications:
- Rich Communication Suite – End-to-End Encryption Specification Version 1.0: This outlines how MLS encrypts RCS messages and content. It covers client encryption and decryption, syncing MLS groups with RCS chats, error handling, and key delivery between providers. It also ties into RCS identity and configuration processes.
- Service Provider Device Configuration Version 11.0: This updates how devices connect to network services, including RCS, with improved certificate handling for secure signaling.
- Rich Communication Suite Endorsement of OMA CPM 2.2 Conversation Functions Version 13.0: This adds client-side notifications for failed decryption of E2EE messages.
- Rich Communication Suite – Advanced Communications Services and Client Specification Version 15.0: This enhances device setup, adds E2EE hooks, and introduces a new “rcs.me” deep link format for chatbots. It also includes unsubscribe/resubscribe options, a “copy to clipboard” action, updated chatbot info for legal compliance, better message reaction handling, and new audio codecs.
GSMA emphasized that RCS Universal Profile 3.0 defines the user experience for these features. It includes E2EE for messages and files, user controls for encryption, and improved spam detection on devices. It also upgrades chatbot interactions with flexible deep links, clipboard actions, and subscription management.
Van Pelt added that RCS still supports cross-platform features like group chats, high-resolution media sharing, read receipts, and typing indicators between iOS and Android.
He concluded,
I’d like to thank everyone who helped shape these specifications. They’re a big step forward for a secure, thriving RCS ecosystem that benefits users worldwide.