What to know about Signal, the chat app US officials used to share attack plans
US officials reacted with shock to revelations in The Atlantic that top members of President Donald Trump’s cabinet allegedly sent detailed operational plans about US military strikes on Yemen to a group chat a reporter had accidentally been added to.
The encrypted messaging platform Signal used to discuss sensitive foreign policy plans has now come to the spotlight.
Here’s what you need to know about it.
What is Signal?
Signal is an open-source private messaging app that allows for direct messaging, group chats, and voice and video calls.
Signal uses end-to-end encryption to ensure all communications of its users remain secure by preventing any third party from viewing or listening, much like other popular chat services like WhatsApp.
In other words, anything sent on Signal is scrambled and only the sender and receiver at each end will have the key to decipher them, and likewise for group recipients.
Signal has other features that allow users to host group calls with up to 40 people, create group chats with up to 1000 people, share stories, and send disappearing messages.
Signal’s encryption protocol is also open source, meaning it’s publicly available for people to inspect, adopt, use or even modify.
The US app originated in 2012 and is supported by Signal Foundation. The nonprofit is funded by donations as opposed to advertisers or investors, and it says it values “privacy over profit”.
Can anyone download it?
Signal is available on most mobile and desktop devices in Australia for anyone to download. The application requires you to sign up using your mobile number, a verification code and a pin-code.
Users must be at least 13 years old to use their services, and there is an option to add further information such as a profile picture and an “about me” section.
How secure is it?
While end-to-end encryption remains a powerful security tool, it is not entirely foolproof.
Stealing encryption keys or accessing data before encryption remain threats, and end-points can become compromised.
Metadata, which includes contextual information about the participants, date, and time the messages were sent, can become exposed too.
Despite this, day-to-day conversation generally remains safe for the average user. Signal says it does “not sell, rent or monetise your personal data or content in any way – ever”.
What information does Signal have about its users?
Signal cannot decrypt or otherwise access any of the content of your messages or calls.
Only encryption tokens are stored on its servers and are used exclusively to send messages and establish calls.
Users also have the option to provide their contacts in order to easily access and connect with other users on their phone.
All users may manage their own personal information in Signal’s application settings.
And any personal data shared with the Signal Support team is kept with it for the purpose of researching the issue and contacting the individual about their case.
