Making Secure Voice Calls on Phone


Nasir is a journalist for Dundun Media. He has just got a lead on the location of a safe house used by AGA and he needs to call the Police. First thing he does is to ensure his call is encrypted. Here's how he did it.

It’s not really a good time for security and privacy. Every attempt at securing communications is being checkmated by several corporations and government agencies. But that isn’t stopping developers from figuring out secure protocols and communication apps.

Signal is a new, open-source Android and iPhone app that promises secure calls. With Signal installed, you and your friend can call each other without your call being eavesdropped, snooped or deciphered.

Installing Signal

For Android Devices

  1. Open the Google Play Store on your Android device.
  2. Search for signal.
  3. Locate and tap the entry by Open Whisper Systems.
  4. Tap Install.
  5. Read the permissions listing.
  6. If the permissions are acceptable, tap Accept.
  7. Allow the installation to complete.

When the installation finishes, you’ll find the launcher for Signal on your home screen or within your App Drawer. Tap the icon to launch the app.

For iOS Devices

  1. Open App Store.
  2. Search for Signal.
  3. Download Signal.
  4. Tap Install.
  5. Read permission listing.
  6. If permissions are acceptable, tap Accept.
  7. Allow installation to complete.

Screen Shot 2016-10-20 at 11.21.03 AM

Note: Signal does not allow the taking of screenshots from within the app.

Using Signal

The first thing you must do is verify your device phone number. When prompted, make sure your phone number is correct and tap Register. Double check your phone number when prompted and then tap CONTINUE.

Once the number is verified, you will be prompted to use Signal as your default SMS app. Tap Use As Default SMS App and then tap YES when prompted. (Remember, you can still send unencrypted texts, so it’s fine to select this app as your default SMS app.) You will then be asked if you want to import the system SMS messages; this will copy all of your phone’s previous SMS messages into Signal’s encrypted database.

How to Initiate an Encrypted Call

If you want to initiate an encrypted call with a contact, first thing to do is to locate and click on the contact. Find the call icon and if you notice a padlock on the call icon, it simply means the other party  has the signal app  and can do encrypted calls. You can also send an invite if the person doesn’t have signal installed.

Continue the conversation.

Visit to post comments and get advice from a community of security experts

Read next article Pretty Good Privacy (PGP)

Summary steps

  • An effective tool for making secured calls to colleagues is Signal. It lets you make calls without the fear of being tracked, eavesdropped, or your calls, deciphered.