RCS Gets Encryption and Video Calls as Apple Joins the Network

The standards body overseeing RCS—the texting protocol meant to replace SMS—has finalized a new version with two significant additions: end-to-end encryption and the ability to make video calls directly from a conversation. The timing matters: Apple added RCS support to iOS 18 in September 2024, the first time the company has offered compatibility with Android messaging in any meaningful way.

What's New in RCS

RCS Universal Profile 3.0 introduced end-to-end encryption using a protocol called MLS (Messaging Layer Security). Think of it like this: ordinary SMS messages are sent in the clear; with MLS, the network operator and anyone intercepting the message in transit cannot read the content. The GSMA, which oversees these standards, positioned this as a major step toward making RCS both secure and usable across different carriers and phone brands.

Beyond encryption, version 3.0 added better support for business messaging—companies can now embed richer interactive elements like scheduling links and payment buttons directly in messages. It also improved audio messaging quality.

Version 4.0, finalized recently, adds video calling. Users will be able to start a video call directly from an RCS conversation, using the same WebRTC technology that powers many video calls on the internet today, but integrated into the carrier's network infrastructure. This is a direct challenge to apps like WhatsApp, Telegram, and Signal, which have dominated video calling since consumer internet calling became reliable.

Why Apple's Move Matters

Apple announced in September 2024 that iOS 18 now supports RCS in its Messages app. For years, Apple had held out, which left Android users seeing green message bubbles (meaning SMS fallback) when texting iPhones, and blue bubbles (iMessage, Apple's proprietary system) when texting other iPhones. The green bubble became a status symbol of sorts—a sign you were texting someone outside the Apple ecosystem.

Apple's support for basic RCS—richer media, better group messaging—removes the largest obstacle to RCS adoption. Enterprise customers who need their employees to text seamlessly across iPhones and Android devices now have a real option. And the social stigma around green bubbles diminishes.

What Apple has not done is support the newer encryption or video calling features in Universal Profile 3.0 and 4.0. The company's implementation focuses on interoperability rather than matching the full feature set of iMessage, which makes strategic sense: Apple wants iMessage to remain a differentiator.

The Carrier Reality Check

Here is where things get complicated. RCS encryption and video calls require substantial upgrades to carrier networks. Carriers need to build systems for managing encryption keys, and they need to integrate video calling with their existing IP infrastructure—the backbone that handles voice calls and data. Many carriers around the world have not yet made these investments.

Rollout timelines differ by region. Major US carriers have offered basic RCS for several years, but encryption and video features depend on carrier modernization plans. European carriers face extra complexity: GDPR regulations require careful handling of encrypted messaging data.

The result is uneven feature availability. Your phone might support video calling, but your carrier might not. Your friend's carrier might support encryption but theirs doesn't. This is reminiscent of the early days of picture messaging (MMS) in the mid-2000s, when you could send a photo to someone on your carrier but not to someone on another carrier. Those problems took years to sort out.

Business Messaging as a Growth Path

Financial services and healthcare companies are interested in RCS for customer communication—they need to be sure messages are logged and senders are verified for compliance reasons. The encryption and interactive features in the newer profiles address those concerns better than SMS ever could.

But RCS faces real competition. WhatsApp Business is already deeply embedded in enterprise workflows. Many companies have built their own messaging solutions. RCS adoption in business depends on three things: devices supporting it, carriers deploying it, and companies deciding it offers real value over what they already use.

Looking at the arc of messaging technology, we have seen this pattern before. SMS seemed destined to fail because early carriers resisted it, but it solved a real problem—text messages worked across any network. RCS is trying to do the same thing: replace SMS with something more capable and secure. The difference is that RCS demands much more infrastructure investment, and it has to compete with entrenched, well-funded alternatives. The path forward is less certain, but Apple's entry into the game changes the odds.

The Technical Foundations

For those interested in the mechanics: RCS encryption uses MLS, which handles group messaging more efficiently than the older method used by Signal and similar apps. With MLS, your phone doesn't need a separate encryption key for every person in a group chat—instead, there's one group key that everyone shares, and it updates securely as people join or leave. This matters because SMS and MMS already work with millions of group messages every day, and RCS needs to handle that scale.

Video calling through RCS integrates with WebRTC, the same standard used by Zoom, Google Meet, and most browser-based video calls. But RCS wraps it in carrier infrastructure, which theoretically means better quality guarantees and fewer connection problems. In practice, that advantage only works if carriers invest in the right infrastructure.

The bigger picture is that RCS Universal Profile 4.0 now offers a feature set competitive with WhatsApp, Telegram, and Signal—secure, with multimedia support, video calling, and business features all built in. Whether it succeeds depends less on technical capability and more on whether people and companies actually adopt it. Apple's move substantially improves those odds.