If you use SMS to communicate sensitive information to contacts, you might want to take advantage of one of the many encrypted SMS services available. One such service is Signal.

With Signal you can communicate via SMS or voice using advanced end-to-end encryption (called TextSecure) with other Signal users. That is the one caveat to using Signal: In order to send encrypted texts with your contacts, they must also be using the app. You can send unencrypted texts to users who are not using Signal, but if you want to take advantage of the offered encryption, those users need to jump on board.

The Signal feature list includes:

  • uses your existing contacts;
  • group chats; and
  • makes private phone calls.

Let’s install this open source app and see how it is used.

SEE: Encryption Policy (Tech Pro Research)

Installing Signal

  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.

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.

When you send an unencrypted text to a user, if that user isn’t using Signal, a message will appear at the top of the chat for you to invite them to use Signal. Tapping that message will enter a text with the download link to the Signal app. Tap Send and the message will go to the contact in question; that contact can easily install Signal to enjoy the offered encryption.

If you decide not to use Signal as your default SMS app, go to Settings | Application Manager | Signal | Open By Default and tap Clear Defaults (Figure A).

Figure A

Clearing Signal as the default SMS app.

The next time you open the app you want to use as the default SMS app you will be prompted to set it (Figure B).

Figure B

Setting the LG G3 messaging app as the default.

To Signal or not to Signal

If you need to communicate sensitive information via SMS, you should be using Signal.