What is Signal? Ultra-secure mobile app approved by Snowden launches video chats

Signal, the ultra-secure smartphone application endorsed by infamous NSA whistleblower Edward Snowden, has announced a fresh update that will give users the ability to make video calls. The feature is currently in beta but will soon be rolled out for wider use.

Developed by US-based non-profit Open Whisper Systems, Signal is well-known in security circles for its strong end-to-end encryption capabilities which effectively protects your text messages and voice chats from unwanted snooping, surveillance and interception.

The firm's founder, computer engineer Moxie Marlinspike, said in a blog post that the evolution to video calling – which will work in a similar fashion to offerings from WhatsApp and Google – represents an "entirely new calling infrastructure for Signal".

He said the move should also increase the quality of its voice calling. The plan, Marlinspike wrote on 14 February, is to roll the update out in stages to help collect feedback from users with different "devices, networks, and regions" to ensure the final release is smooth.

How to use video calls on Signal

The video calling beta will only work between users who have enabled the capability. It can be activated simply – on both Apple iOS and Google Android – by going to: Signal Settings > Advanced > Video calling beta.

Yet for an app that was developed for privacy-conscious users, Open Whisper Systems admits the update may bring with it some security concerns. In some cases, metadata may be collected by technology firms, it warned.

Using the iPhone as an example, when a user enabled the new video calling feature on iOS it will let them take advantage of a new function called "CallKit", which will leave call logs stored in the device's "recent calls" list.

Marlinspike said this was due to iOS treating CallKit "like any other call" and noted it could mean some information will then also be synced to iCloud if this function is turned on. Such data would include who was called, call duration, and their number.

Luckily, this is feature offers an opt-out option, and can be disabled at: Settings > Advanced > Use CallKit. Recently, a Russian phone-cracking firm, Elcomsoft, claimed Apple was storing iCloud logs after they had been deleted, in some cases for over a year.

Open Whisper Systems continues to be an industry-standard for secure communications, and this is unlikely to change with the latest updates. Its open-source code is used to bolster the security of other major applications designed by WhatsApp, Google and Facebook.