Google recently announced its adoption of Messaging Layer Security (MLS), a system that enables end-to-end encryption for messaging apps. This move could lead to cross-platform chat encryption in Google’s Messages app, allowing users to securely exchange messages with other apps that also support MLS. European regulators are pushing for tech companies to implement such encryption systems to ensure secure messaging between platforms.
To achieve meaningful interoperability, major companies need to back the same encryption standard, and MLS seems to have gained significant support. Google also supports RCS (Rich Communication Service), a carrier-backed end-to-end encrypted messaging system. While RCS initially lacked proper security for group chats, Google is now releasing a version that addresses this issue, although it doesn’t use MLS.
One significant problem MLS aims to solve is better encryption for group messages. A 2017 Oxford paper highlighted security concerns in major messaging apps like WhatsApp, Facebook Messenger, and Google Allo, where group messages could be intercepted if even one member’s device is compromised. To address this, researchers devised an “Asynchronous Ratcheting Tree” concept to enhance the security of end-to-end group messages, which influenced the development of MLS.
The MLS protocol was developed by the Internet Engineering Task Force (IETF), a standards organization. In March, the IETF approved the publication of the MLS specification (RFC 9420) after testing draft versions in Webex and RingCentral chats.
Google intends to make its MLS implementation open source and incorporate it into Android’s codebase. However, the company has not specified when this will happen or how RCS messages, which Google has championed for over a year, will work with MLS-based encryption. Google has consistently criticized Apple for not supporting RCS, a messaging service that is now available to over 800 million Android users. It remains to be seen if other tech companies will follow suit and adopt MLS.
Overall, the adoption of MLS by Google’s Messages app has the potential to bring secure cross-platform chat encryption to millions of users. With MLS, users can expect enhanced security for group messages, protecting their privacy and ensuring sensitive information remains confidential during conversations. By implementing MLS, Google is taking a step towards meeting the demands of European regulators and the growing importance of secure messaging solutions.
