RCS Standard: A New Era of Mobile Communication and Security Challenges
SMS has been the backbone of mobile communication for over a decade – but it does not support high-definition media, group chats, or read receipts. RCS (Rich Communication Services) – a protocol developed by the GSMA association, operates over Internet Protocol (IP) and is designed to replace SMS and MMS. It transforms the standard messaging app into a modern communication tool: high-quality photos, typing indicators, read receipts – features that until now were only offered by apps like “Messenger” or “WhatsApp.”
1. From Fragmentation to a Universal Standard
The origins of RCS date back to 2008, but the road to success has been bumpy. Initially, different operators deployed their versions, which did not work together. The breakthrough came in 2016 when the GSMA introduced the Universal Profile – a common set of rules ensuring compatibility worldwide.
The biggest push came from Google, which took the initiative and integrated RCS into the Android ecosystem through the “Jibe” platform. This allowed bypassing operator barriers and offering a unified experience to billions of users.
2. Apple’s Move and the Impact of EU Regulations
For many years, Apple ignored RCS, preferring its closed “iMessage” system (the “blue bubbles”). However, the European Union’s Digital Markets Act (DMA) forced tech giants to open their platforms.
Starting with the “iOS 18” version, iPhones finally support RCS. This means that when communicating between iPhone and Android:
- High-definition photos and videos are sent.
- Group chats and reactions work.
- Read and typing indicators are visible.
However, there is an important nuance: Apple clearly states that the current RCS implementation on “iOS” devices does not have end-to-end encryption, unlike “iMessage.”
3. Security: Is RCS Private?
The security situation in the RCS world currently depends on the platform used.
Encryption Status
- Google Messages: When both parties use Android and Google Messages, conversations are fully encrypted (E2EE). Neither operators nor Google can see the content.
- Cross-platform (Android <-> iOS): Currently, when communicating between different operating systems via RCS, messages are usually not end-to-end encrypted. They travel through operator servers, where they can theoretically be seen.
Future Prospects: MLS Protocol
The GSMA has approved a new version of the standard (Universal Profile 3.0), which includes the implementation of the MLS (Messaging Layer Security) protocol. This should ensure secure, encrypted communication between different platforms – for example, between Google and Apple apps – but this process is just beginning.
4. Comparison: RCS, iMessage, and Apps
Here’s how RCS stacks up against the main competitors in the market:
| Feature | RCS (Universal Profile) | Apple iMessage | Signal / WhatsApp (OTT) |
|---|---|---|---|
| Nature | Open industry standard | Closed Apple ecosystem | Third-party app |
| Technology | IP (SIP/MSRP + HTTP) | IP (via Apple ID) | IP (phone number/account) |
| Security (E2EE) | Fragmented (depends on the app; future – MLS) | Always (between Apple devices) | Always (Signal protocol) |
| Compatibility | Universal (Android, iOS) | Only Apple (works as SMS elsewhere) | Universal (not OS-dependent) |
| Privacy (Metadata) | Depends on operator infrastructure | Limited within Apple ecosystem | Signal – minimal; WhatsApp – extensive |
Conclusions
RCS finally connects Android and iOS users into one modern network and significantly improves the daily messaging experience. The functionality is already at a high level, but encryption between different platforms remains a weak point – until the MLS standard is implemented. For those who value privacy today, third-party apps like Signal are still a safer choice, but RCS is rapidly catching up.