How end-to-end encryption in Google Messages provides more security

Google Messages supports end-to-end encryption when messaging other users using Google Messages over Rich Communication Services (RCS). When available, RCS messages and their attachments, such as photos and videos, will be end-to-end encrypted. End-to-end encryption is a security method that keeps your communications secure. With end-to-end encryption, no one, including Google and third parties, can read eligible messages as they travel between your phone and the phone that you message.

To use end-to-end encryption in Google Messages, you and the person or group that you message must both:

• Use the Google Messages app.
• Have RCS chats turned on.
• Use data or Wi-Fi for RCS messages.

Tips:

• Text messages are dark blue in the RCS state and light blue in the SMS/MMS state.
• End-to-end encryption is automatic in eligible conversations.
• You'll see ' RCS chat with [contact name or phone number]' when end-to-end encryption is active in a conversation. Your messages will also include a lock on the send button.

Important: End-to-end encryption isn't available for SMS/MMS messages.

The secret key is a number that's:

• Created on your device and the device that you message. It exists only on these two devices.
• Not shared with Google, anyone else or other devices.
• Generated again for each message.
• Deleted from the sender's device when the encrypted message is created and deleted from the receiver's device when the message is decrypted.

Neither Google or other third parties can read end-to-end encrypted messages because they don't have the key.

Each end-to-end encrypted conversation has a unique verification code. This code must be the same for you and your contact to verify that your messages are end-to-end encrypted.

If you have a lock on the send button when you compose a message and next to the message's timestamp, end-to-end encryption is used.

If you or your contact lose RCS chats, end-to-end encryption is no longer possible for messages that you send or receive. If that happens, you won't have a lock next to the timestamp of the conversation's latest message or on the send button when you compose a message.

Learn how to control the way that messages are sent when end-to-end encryption isn't available.

Once an RCS conversation becomes end-to-end encrypted, it won't revert to SMS messages unless you or your contact lose or disable RCS, or switch to a new phone or operating system. End-to-end encrypted messages can only be delivered over data or Wi-Fi. If you or the person who you're messaging lose data or Wi-Fi, the conversation will downgrade to SMS. Once both conversation participants regain access to RCS, and assuming both participants are still using Google Messages, the conversation will automatically switch back to end-to-end encrypted RCS.

You can send an SMS instead or wait until you or the person who you're messaging gets RCS again.

Note: SMS/MMS messages are not end-to-end encrypted, nor is RCS if the messaging app does not support it. Currently, only Google Messages supports end-to-end encrypted RCS, but the industry is working towards making end-to-end encrypted RCS available more broadly.

End-to-end encryption is automatic in eligible conversations, so Google Messages won't disable other features that help with your message experience, like Google Assistant suggestions, spam detection and automatic previews.

With your permission, some Google and third-party apps can access your messages to provide seamless companion experiences like when you restore your messages to a new phone or app, or when you send message notifications to your home device, smartwatch or car.

When end-to-end encrypted messages are received on your phone, they’re also included in Android backup and accessible to apps you’ve granted SMS or notifications permissions to. You can manage which apps can access your messages.  

• Use end-to-end encryption in Google Messages
• Control message delivery
• Control message storage and access
• Change your Google Messages notifications and settings
• Technical paper: Messages end-to-end encryption