Apple Expands RCS Encryption and Memory Protections in iOS 26.4

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A new developer beta of iOS and iPadOS introducing support for end-to-end encryption (E2EE) in Rich Communications Services (RCS) messages has been released by Apple.

The update, available in iOS and iPadOS 26.4 Beta, allows encrypted RCS conversations between compatible Apple devices, with a broader rollout planned for iOS, iPadOS, macOS and watchOS in a future software update.

RCS Encryption Enters Beta Testing

"End-to-end encryption is in beta and is not available for all devices or carriers," Apple clarified. "Conversations labeled as encrypted are encrypted end-to-end, so messages can't be read while they're sent between devices."

At present, encrypted RCS messaging can only be tested on Apple devices and does not extend to Android.

The move follows the GSM Association's formal announcement last year backing E2EE for RCS messaging.

Supporting the standard will require Apple to adopt RCS Universal Profile 3.0, which is based on the Messaging Layer Security (MLS) protocol.

Expanded Memory Protections and Security Defaults

Beyond messaging, the beta introduced an update to Memory Integrity Enforcement (MIE). Applications can now opt in to the full protections of MIE, moving beyond the previously available Soft Mode.

Apple first unveiled the security feature in September 2025 as a defense against sophisticated mercenary spyware and described it as providing always-on memory safety protection across critical attack surfaces, including the kernel and more than 70 userland processes, without performance trade-offs.

Read more on RCS encryption: Google Introduces New AI-Powered Scam Detection Features for Android

Separately, a report from MacRumors indicated that iOS 26.4 is expected to enable Stolen Device Protection by default for all iPhone users. The feature requires Face ID or Touch ID authentication for sensitive tasks such as accessing stored passwords and credit cards when away from familiar locations.

Stolen Device Protection also introduces:

  • A one hour delay before allowing Apple Account password changes

  • Biometric authentication requirements for key security actions

The delay is designed to give users time to mark a device as lost if it is stolen.

The iOS and iPadOS 26.4 SDK is bundled with Xcode 26.4, available via the Mac App Store, and includes additional developer-facing updates, bug fixes and known issue documentation across areas such as SwiftUI, StoreKit and networking.

Image credit: Poetra.RH / Shutterstock.com

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