Signal app: WhatsApp messaging alternative recommended by Elon Musk explained - who owns it and is it secure?

The tech tycoon has urged his followers to download the messaging app, which has been instrumental in demonstrations around the world

Elon Musk – business magnate and CEO of SpaceX and Tesla – has tweeted urging people to “Use Signal” in light of a change in policy from messaging service, WhatsApp.

WhatsApp prides itself on its secure end-to-end encryption, but last week worried users by announcing changes to its terms and conditions that allow users’ data to be shared with businesses they communicate with that are also using Facebook.

While users in the UK will not be affected by these changes, for users in other regions the changes are mandatory, and anyone who hasn’t agreed to them by 8 February 2021 could see their account deleted.

Graffiti urging people to use Signal spray-painted on a wall during a protest at the University of California, Berkeley in 2017, in response to a scheduled speech by controversial Breitbart writer Milo Yiannopoulos (Photo: Elijah Nouvelage/Getty Images)

But now Musk has made his millions of social media followers aware of Signal, another end-to-end encrypted messaging service that is so secure, it’s used by high-ranking public officials and news outlets.

Here is everything you need to know about it.

What is Signal?

(Photo: Shutterstock)

Signal has been around for a few years, first launching in 2014. But it’s only really been since the George Floyd and Black Lives Matter demonstrations of summer 2020 that the app has really gained ground.

One of the app’s first major proponents in 2020 was Jack Dorsey, the CEO of Twitter who recommended users download Signal in response to heightened awareness of police monitoring of other communication-based apps.

The first week of June 2020 saw the app log five times as many downloads as it had in the days prior to the death of Floyd.

As the apps’ popularity continued to grow, its creators announced a feature which allowed users to blur faces in photos, as police ramped up their efforts to monitor the communications of protestors.

All of the usual features of end-to-end encrypted messaging services are present and correct with Signal, but it also carries a few interesting features of its own.

One popular feature is the app’s ability to allow users to set a kind of ‘self destruct’ timer to messages, meaning after an interval – which can be between five seconds and a week long – the messages will be deleted from both the sender's and the receivers' devices.

Signal’s developers said this feature had been developed for users who “want to automate minimalist data hygiene”, and is not designed for “situations where your contact is your adversary".

Who makes the app?

Signal was first launched under the name TextSecure by Whisper Systems, an American startup co-founded by security researcher, Moxie Marlinspike.

But in its current guise, Signal is actually developed in part by Brian Acton, the US computer programmer and Internet entrepreneur who co-founded WhatsApp.

Less than six months after leaving WhatsApp parent company Facebook in late 2017, Acton announced that he had teamed up with Marlinspike to found the Signal Foundation.

The Signal Foundation describes itself as a nonprofit organisation with a mission "to support, accelerate, and broaden Signal's mission of making private communication accessible and ubiquitous".

The company was set up with $50million in funding from Acton – the 836th richest person in the world – and now runs totally on donations as a nonprofit business.

Is it safe?

All communications on Signal are automatically end-to-end encrypted, with the ‘keys’ used to encipher users communications generated and stored on their devices, rather than on a remote server.

It is so secure in fact, that in 2017 Signal was approved by the US Senate for use by senators and their staff, and a year earlier had been used by Hillary Clinton's presidential campaign, which instructed staff to use the app when saying “contentious or disparaging" things about rival nominee, Donald Trump.

Outside of politics, the app’s security means Signal has also found audiences in some surprising places.

Last summer, it was the most downloaded app in Hong Kong after the government's controversial passing of a new national security law, and the app is often used to securely provide anonymous news tips to major media outlets.