Ironically, a major uncertainty is E2EE itself. This is now being probed by the UK government, which has decided to use Apple as its test case in a campaign to introduce backdoors into the encryption used in iCloud services. So far, Apple is resisting, choosing to disable security rather than allow surveillance. Talks are reportedly ongoing.

With the GSMA releasing new RCS specs, Apple pledges to 'add support for end-to-end encrypted RCS messages to iOS, iPadOS, macOS, and watchOS in future software updates.'

When Apple added RCS support to iOS 18, the company used an older version of the protocol. This caused chat messages between iPhone and Android users to be unencrypted. Fortunately, Apple has already agreed to update to the latest RCS protocol, thereby permanently fixing the issue.