Earlier today at the I/O conference, Google announced a new chat app called Allo, complete with an "incognito" mode that boasts full end-to-end encryption. But the technology powering that encryption is more familiar than many Google fans may realize.
After the new app was announced, Open Whisper Systems revealed in a blog post that the company has been actively participating in the development of Allo's incognito mode, and the resulting feature will be built on top of the company's open Signal protocol. "We've been collaborating together on the integration of Signal protocol into Allo, which will bring all of Signal Protocol's strong encryption properties to Allo's incognito mode," the company wrote in a blog post. "We'll provide more technical details and a summary of the integration when the app is available."
The Signal protocol is available under an open-source license and already serves as the backbone for a number of popular chat products. The largest of those products is WhatsApp, which finished its shift to full end-to-end encryption earlier this year, after an active collaboration with Open Whisper. Open Whisper also operates a separate standalone messaging app called Signal. The protocol has withstood a number of independent audits, and is generally considered to be secure.
Allo's implementation of Open Whisper's technology differs significantly from WhatsApp and Signal. Messages sent in Allo are not end-to-end encrypted by default, and users can switch seamlessly between private and unprotected channels, which has led to some concern that users might send unprotected messages by mistake. WhatsApp's implementation, in contrast, does not allow users to downgrade to an unprotected channel once a secure connection has been established.
Allo is scheduled to be released later this summer.