Google is making RCS available worldwide and adding end-to-end encryption
Google’s implementation of RCS through the Messages app is now available worldwide, with the exception of a few countries such as China and Russia. Google also announced that it will provide end-to-end encryption for RCS messages and is starting a beta test.
In a blog post, Google writes that RCS through Messages is now available worldwide, through Google or through the user’s provider. In doing so, the company notes that the availability of RCS ‘depends on the device of the user and the provider’. In addition, Google Messages has published a map showing the countries where the chat functions are available. According to this map, RCS is not available in countries such as China, Russia and Iran.
Google also announces that it wants to provide the RCS messages in Messages with end-to-end encryption. The messages are now encrypted, but not end-to-end. First, users who have a one-to-one conversation via Messages receive end-to-end encryption. Google is rolling out this form of encryption to the first beta testers this month, a rollout that won’t be ready before the end of the year. It is not clear when regular Messages users can expect the encryption. Messages conversations that qualify for end-to-end encryption will receive this encryption automatically. Only when both users RCS chat through Messages app can the conversation get the encryption.
The company has released a technical paper explaining how end-to-end encryption of Messages works. For example, Messages uses the Signal protocol to encrypt the messages. WhatsApp and Facebook Messenger, among others, use this protocol for end-to-end encryption.
In the paper, Google also explains how the user can recognize the end-to-end encryption. Google uses a lock icon for this, for example with the timestamp of a message. Users can switch to another RCS chat app after using Messages end-to-end encryption, although the first message per conversation will be an unreadable string of numbers and letters stating that it is an encrypted message . However, according to Google, the sending party’s Messages app will be able to see from the plaintext delivery receipt that the receiving user has switched to a different RCS app, so the next message will no longer have end-to-end encryption.
RCS, short for rich communication services, is seen as the successor to SMS. RCS makes it possible to send messages over the internet, with additional features similar to other chat apps. For example, users can make video calls via RCS, receive read receipts and send images. Until mid-last year, providers were responsible for the rollout of RCS, but in June 2019 Google indicated that it wanted to distribute the chat implementation itself.
On the left an SMS or MMS conversation via Messages, in the middle an RCS conversation, on the right an end-to-end encrypted RCS conversation