How RCS chats keep your conversations secure

When you use RCS chats by Google, messages are sent and received through Google’s RCS infrastructure over the internet. Messages can either be delivered to or received from users on other RCS service providers. If RCS chats are provided by Google, but your recipient’s RCS service is with another provider, your messages are routed through Google’s RCS infrastructure and then routed to your recipient's RCS infrastructure.

Delivery of SMS and MMS messages, which are always sent through your carrier, won't change as part of your use of RCS chats.

To make sure your messages are properly delivered, Google uses information like your phone number, device identifiers, and SIM card number. This data may be stored for about a month to keep you connected to RCS and in cases where you temporarily go offline.

RCS chats between Google Messages users are end-to-end encrypted by default. Learn how to use end-to-end encryption in Google Messages. The GSM Association (GSMA) sets Mobile and RCS standards, and we are currently working to define security standards cross platform.

RCS chats by Google uses Transport Layer Security (TLS) encryption to protect your messages even when end-to-end encryption is not available. This means that anyone trying to intercept your messages between you and Google would only be able to find encrypted, unreadable text.

RCS chats you send using Google’s RCS infrastructure are temporarily queued for delivery and deleted after they’re delivered. For undelivered RCS messages, you can switch to SMS or MMS provided by your carrier, in which case the corresponding RCS message is deleted from the queue.

Google’s RCS infrastructure sends and temporarily stores files like images, videos, GIFs, and stickers with random, unguessable URLs. These links aren't shared with you or the person receiving your message. To prevent connections between the hosted file and your phone number, Google uses a special algorithm (hash function) that transforms these URLs and makes it very difficult to associate the file and your phone number.

• If your message’s compose bar says "RCS message," your message will be sent through RCS from either Google or from your carrier’s RCS service.
• If your message’s compose bar says "Text message," your message will be sent through your carrier as SMS/MMS. Conversations will have "SMS" or "MMS" below the send icon.

Important: After you remove your SIM card, RCS chats may still work for about 8 days.

1. Open Google Messages .
2. Tap your profile photo or icon Messages settings.
3. Tap RCS chats.
   • Tip: If you can't find "RCS chats," tap Chat features.
4. Turn on RCS chats.

When you turn RCS chats off, other functions like typing indicators and read receipts also turn off.

1. Open the Samsung Messages app.
2. Go to Menu  Settings.
3. Tap RCS chats settings.
4. Turn Rich Communication Settings (RCS) on or off.