From Macrumors “When it comes to security though, iMessage still holds the upper hand. It offers end-to-end encryption for all communications between Apple devices. RCS, while offering improved encryption compared to traditional SMS, doesn't quite reach the same level of security as iMessage.”

Also “Another area where iMessage still maintains an edge is in its immediate availability across all Apple devices. RCS, on the other hand, depends on carrier support and implementation on both ends of the conversation. This means that while RCS promises a more unified messaging experience, its availability might not be as universal as iMessage is within the Apple ecosystem, at least initially.”

So, yes, it is encrypted but not to the same level as end to end among Apple devices. And features, including security, will vary based on implementation of the various device manufacturers. Fragmentation has always been the biggest weakness to Android IMHO.

So, the silly green bubble theory is still valid from alerting iMessage users to potential security issues.


https://www.macrumors.com/2024/07/09/rcs-messaging-explained-ios-18/