Signal is the privacy messaging smartphone app that everyone seems to be using. You can also use Signal on a Windows, Mac – or Linux PC. It is easy to install and register to your Signal account.
Privacy by Design
The sign is published by the Signal Foundation and Signal Messenger LLC. These two nonprofits – based in Mountain View, California – were founded by Matthew Rosenfeld (aka ‘Moxie Marlinspike’) and Brian Acton. Together, they continue the work started at Open Whisper Systems, one of Rosenfeld’s first start-ups.
The Signal application is free and open source. Anyone can review the source code. The source code for the Signal Messenging Protocol (SMP) was reviewed by a joint team from the German CISPA Helmholtz Center for Information Security, Swiss ETH Zurich University, Cisco and Canadian University of Waterloo. They declared clean code, pure motives and rock solid encryption. The signal is definitely safe.
But there is a difference between security and privacy.
RELATED: What is a sign and why is everyone using it?
The difference between privacy and security
Privacy means controlling your information and data, choosing who has access to it and deciding what they can do with it. Security is one of the techniques you can use to maintain your privacy.
The security provided by SMP is so strong that other apps, like WhatsApp, have adopted the Signal protocol to provide end-to-end encryption for their own products. But while WhatsApp can be safe with regard to the transmission of your messages, this does not address any privacy concerns. The security of the protocol has nothing to do with WhatsApp’s data collection and sharing policy. It is these activities that affect your privacy, and it is the prank that catapulted WhatsApp in the public eye and the worst public relations storm in its 11-year history.
Whatsapp collects and records data about you and using their app. The company stores this data – including your contact list, who you contacted, details of purchases you made through the app, and your location when you use the app – on their servers. Therefore, although the delivery of your messages is secure, WhatsApp keeps a lot of private data about you. And WhatsApp is owned by Facebook.
In contrast, Signal holds virtually nothing about you. It stores the number of the smartphone you registered with, when you signed up to use Signal and when you last used the service. That’s it. A phone number and two timestamps. So even if they are hit by a subpoena, that is all they can deliver to the authorities. Nothing about your messages, your location or anything else.
The signal starts to make a lot of sense when you scratch the surface of how your data is often used as merchandise by other companies.
Installing Signal on Linux
There is only one way to sign up for Signal, and it is through your smartphone. Works on Android phones and iPhones. So, if you don’t have Signal installed on your smartphone, do it first. It must be working on your smartphone before you can use it on your computer.
The signal is available in the repositories for some Linux distributions. It is also available as a flatpak and a snap. Let’s install snap on Ubuntu.
sudo snap install signal-desktop
You can use snap in Fedora too, but to cover all the bases, let’s demonstrate the installation of flatpak.
sudo flatpak install https://dl.flathub.org/repo/appstream/org.signal.Signal.flatpakref
In Manjaro, you can install it directly from pacman.
sudo pacman -Sy signal-desktop
Starting signal on the desktop
Press the “Super” key on the keyboard. It is usually between the “Control” and “Alt” keys at the bottom left of the keyboard. Type “sign” in the search bar. You will see the signal icon.
Click the icon to start Signal.
Before using Signal on your computer, you need to link it to the Signal application on your smartphone. The desktop client displays a QR code. You need to scan this code with your smartphone from within the Signal application. (The QR code in the screenshot below is not an actual Signal QR code.)
Below the QR code, there are brief instructions for Android phones and iPhones.
On your smartphone, open the Signal app and tap the menu button.
Tap the “Settings” entry in the menu.
Touch the “Linked devices” option.
You will see a list of the devices that you have already linked to this Signal account.
Touch the blue “+” button to add a new device.
The Signal QR code reader is displayed.
Scan the QR code on the desktop client. When the QR code is scanned and decoded, you will be asked if you are sure you want to link the device to your Signal account.
Touch the blue text “Connect device”. In the desktop client, you will be asked to provide a name for the device.
Click on the “Complete phone link” button when entering the name by which you want the customer to be known. This is the name that will be listed in the “Linked devices” list on your smartphone. It has no effect on your identity on Signal.
Signal will sync your contacts and groups of messages from your smartphone. Note that it does not pull existing chats and messages. Only messages that arrive after the desktop client is linked to your Signal account will appear on the client.
When finished, it will display them in the main client window. If you prefer dark mode, click File> Preferences> Dark.
Signal is now ready for you to send private, secure messages right from your computer.
Unlinking the Desktop Client
If desired, you can remove the desktop client from your Signal account. You can do this from your smartphone or from the desktop.
On your smartphone, touch the menu button> Settings> Linked devices, then touch the linked device you want to remove. Tap “OK” in the small pop-up box.
If you prefer to break the desktop client link, click File> Preferences> Clear data.
Desktop security and privacy
Messaging apps are great. But when you’re sitting at a computer, it can be more convenient to have the app on your desktop so you don’t have to switch between your computer and your smartphone.
Now you can enjoy Signal’s guaranteed security and privacy and a real keyboard.