Apple's latest iOS 26.4 beta introduces end-to-end encryption testing for RCS messages, but the secure green bubbles remain confined to iPhones only for now. The feature, which began rolling out to developers this week, marks Apple's first step toward securing cross-platform messaging that has long been criticized for its security gaps.
The encryption toggle appears in Settings by default for developers running iOS 26.4 beta, with a lock icon indicating when conversations are protected. However, during this initial testing phase, encrypted RCS messaging works exclusively between Apple devices where iMessage is disabled.
Android users cannot participate in these secure conversations yet, despite RCS being primarily designed for iPhone-to-Android communication.
"RCS encryption is available for testing between Apple devices and is not yet testable with other platforms,"
Apple confirmed the feature "is not shipping in this release" and will arrive in a future software update across iOS, iPadOS, macOS, and watchOS. The company stated that it was leaving cross-platform testing for a later date.
The GSM Association, which oversees the RCS standard, announced in September 2024 that it was working on bringing interoperable end-to-end encryption to the RCS Universal Profile standard. The specification for E2EE using the Messaging Layer Security (MLS) protocol was finalized and released in March 2025 with RCS Universal Profile 3.0.
Google first implemented its own end-to-end encryption on top of RCS in 2020 and confirmed in 2024 that cross-platform encryption between iPhone and Android was in development. Android devices have supported secure RCS chats internally for years, but Apple's initial RCS implementation used version 2.4 of the Universal Profile standard, which lacked built-in encryption protections.
Full implementation requires Apple to upgrade to RCS Universal Profile 3.0, a newer standard that includes end-to-end encryption. The testing phase that began this week represents Apple's first move toward implementing the RCS Universal Profile 3.0 standard finalized in March 2025.
