How to Use Signal

Signal is one of the best apps to avoid surveillance and communicate safely with your friends.
November 27, 2017, 2:00pm

This short video and explainer is summarized from The Motherboard Guide to Not Getting Hacked , our comprehensive guide to digital security.

Signal is one of the best apps for privacy because it protects your messages from snoopers and because it’s extremely easy to use. Signal encrypts your message on your phone and decrypts it on the phone of the person you’re messaging with, ensuring that no one else can access it (this is called end-to-end encryption). Signal also allows you to make encrypted calls.


Using Signal is really easy. The first thing you need to do is download the app from the App Store or from Google Play. Once that’s done, you have to register your number with the app.

If you are someone who’s worried about stalkers and harassers, you might want to avoid giving out your personal phone number to strangers, and use Signal with a different number.

Good news: it’s pretty easy to do that too.

The first option is to use a Google Voice number that you will associate with Signal. The other is to buy a second SIM card, and hence a second phone number. Put that in your phone, register to Signal and then swap in your regular SIM.

You can now give out your secondary phone number as a Signal point of contact.

When you open the app, it will show you which one of your friends from your address book already use it. At this point, Signal acts just like any other messaging app: just tap your message and send it to your friends!

The cool thing is that the messages, even if they’re intercepted while traveling over the internet, cannot be read. And there’s some extra features like the possibility to set a timer so messages disappear from your friend’s phones after a certain amount of time.