Google’s MVNO cell phone service, Google Fi, is getting a surprising new feature: encrypted phone calls. Encrypted voice chats via messaging apps have been available for a while, but this is the first time a company has hacked the mainstream phone system for end-to-end encrypted conversations. Open the phone app, choose a number and your call can be encrypted.
End-to-end encryption is not a normal phone standard, so both interlocutors must be firmly in the Google Fi ecosystem for the feature to work. Google’s description says that “calls between two Android phones on Fi are secured with end-to-end encryption by default.” Google Fi also works on iPhone, but since Google is supposed to use Apple’s default phone app, it can’t add encryption.
For encrypted Fi-to-Fi calls, Google is showing a new message “Encrypted by Google Fi” in both users’ phone apps, along with the ubiquitous lock icon. The company says there will also be “unique audio cues”.
Google doesn’t explain how the encryption works, but presumably the feature is tied to Wi-Fi or VoLTE (Voice over LTE) calls. It would be difficult to do this over traditional voice networks, but if you run the voice call over data and control both client apps, it makes it a lot easier to wrap the whole session in encryption. I wonder if encrypted calls are billed as Fi’s metered data usage rather than unlimited calling minutes.
Google says the feature will roll out to Android devices “in the coming weeks.”