Apple's Encrypted RCS Messaging Comes to iOS 26.4 Beta

Key Findings

• Apple is testing end-to-end encrypted Rich Communications Services (RCS) messaging in the iOS and iPadOS 26.4 developer beta.

• The feature is still in beta and not yet available to all devices or carriers.

• Encrypted conversations are labeled as such and cannot be read while in transit between devices.

• RCS encryption is currently only available for testing between Apple devices and not with other platforms like Android.

• The RCS encryption is based on the Messaging Layer Security (MLS) protocol and requires Apple to update to the RCS Universal Profile 3.0.

Background

RCS is a modern successor to SMS/MMS, using mobile data or Wi-Fi instead of basic cellular signaling. It brings chat app features like read receipts, typing indicators, high-res media sharing, group chats, and end-to-end encryption (when supported). RCS has been widely adopted on Android, and Apple's support for it could improve future iPhone-Android messaging capabilities.

The inclusion of RCS encryption in the iOS 26.4 beta comes nearly a year after the GSM Association (GSMA) formally announced support for end-to-end encryption to safeguard messages sent via the RCS protocol.

RCS Encryption Implementation

• The RCS encryption feature in iOS 26.4 beta is enabled by default but may not be available for all users during the testing period.

• In the initial implementation, RCS encryption is only available for communication between iPhone users who have iMessage disabled.

• Apple notes that the RCS encryption capability will gradually roll out to more beta users throughout the testing period.

Memory Integrity Enforcement (MIE) Updates

• iOS 26.4 beta also includes a new feature that allows applications to opt in to the full safeguards of Memory Integrity Enforcement (MIE) for enhanced memory safety protection.

• Previously, applications were limited to Soft Mode for MIE, but the new beta enables the option for the full MIE protection.

• MIE was introduced by Apple last September as a way to counter sophisticated mercenary spyware attacks by offering "always-on memory safety protection" across critical attack surfaces.

Stolen Device Protection Updates

• According to reports, iOS 26.4 is also expected to enable Stolen Device Protection by default for all iPhone users.

• The feature adds an extra layer of security by requiring Face ID or Touch ID biometric authentication for sensitive actions when the device is away from familiar locations.

• Stolen Device Protection also adds a one-hour delay before making Apple Account password changes to give users time to mark their device as lost if stolen.

Overall, the introduction of end-to-end encrypted RCS messaging in the iOS 26.4 beta, along with the MIE and Stolen Device Protection updates, demonstrates Apple's continued efforts to enhance the security and privacy of its mobile platform.

Sources

• https://thehackernews.com/2026/02/apple-tests-end-to-end-encrypted-rcs.html

• https://securityaffairs.com/188105/security/encrypted-rcs-messaging-support-lands-in-apples-ios-26-4-developer-build.html

• https://www.macrumors.com/2026/02/16/ios-26-4-rcs-encryption-testing/

• https://appleinsider.com/articles/26/02/16/new-in-ios-264-beta-1-videos-in-podcasts-playlist-playground-rcs-more

• https://appleinsider.com/articles/26/02/16/rcs-encryption-surfaces-in-ios-264-developer-beta-but-testing-is-extremely-limited

• https://www.theverge.com/tech/879792/apple-iphone-android-rcs-messages-end-to-end-encrypted