Google Messages will support the Messaging Layer Security (MLS) protocol, enabling end-to-end encryption of messages across different platforms. This update is in response to the new EU regulations concerning interoperability under the Digital Markets Act.
Rich Communication Services (RCS), which was introduced on Android in 2019, replaced traditional SMS and MMS with encrypted communication, read receipts, and typing indicators. However, RCS encryption requires both parties to use the same platform for secure communication.
To address this limitation, Google announced last year its integration of the MLS protocol, ensuring encrypted communication for both one-on-one and group chats across applications and platforms.
According to Android Authority, code lines and flags associated with MLS were found in the Google Messages application code, indicating an upcoming feature addition. Google’s intention is to standardize MLS as a security measure for messages.
The development of MLS is being undertaken in various programming languages such as C++ (Mlspp), Go (Go), and Rust (Openmls), leveraging existing encryption protocols like S/MIME, OpenPGP, Off-The-Record, and Double Ratchet. MLS support is already present in Webex and Ringcentral platforms, with integration into Wickr and Matrix projects on the horizon.
The primary objectives of the MLS protocol include:
- Confidentiality: Only group members can access messages.
- Integrity and authentication guarantees: Messages are sent by trusted sources and remain unchanged during transmission.
- Group member authentication: Participants can verify the identities of other group members.
- Asynchronous operation: Encryption keys can be shared without simultaneous online access from all group members.