Signal secures all your conversations with end-to-end encryption and offers more privacy and security than your average chat app. But Signal offers some other useful security options. Here̵
Turn on registration lock to protect your signal account
Your Signal account is linked to your phone number, you don’t need a password at all. When you first register for Signal (or re-register a device at a later stage), Signal will verify who you are by sending a code to your number. Enter the code to prove you are who you say you are and that you are ready to go.
But what happens if someone gains access to your phone number? While this may seem like an unlikely event, it is within the possibilities. Someone could steal your smartphone’s SIM card or fool your phone service provider into transferring your number to a new SIM card using social engineering techniques.
With access to your phone number, someone can access your entire Signal account. They couldn’t see your old conversations, but they could pretend to be you or receive messages intended only for you. Depending on what you’re using Signal for, this can be uncomfortable, embarrassing, or utterly devastating.
Fortunately, you can enable Registration Lock within Signal so that any attempt to reregister your phone number also requires your PIN. Her very important that you choose a memorable PIN in this case. It is advisable not to write this down. If necessary, keep it in a safe place, such as in a password manager.
To enable Registration Lock, launch Signal and tap your profile icon in the top left corner of the screen. Choose Privacy, then turn on Registration Lock and read the warning. Signal will tell you that if you get your PIN wrong when re-registering, you will not be able to access your account for a week.
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Check who you are talking to
Unlike other messaging apps, Signal lets you verify who you are talking to using a series of codes known as security numbers. To view the security numbers for a call, tap the contact’s name at the top of a call and choose View security number on the next screen.
The best way to verify that the person you are talking to on Signal is who it claims to be is to personally verify their identity. Both people should open the corresponding conversation, tap the other party’s name, then choose ‘View security numbers’.
From here, you can compare the numbers you see on your screen to verify that you are both in the same conversation. Tap the QR code to launch the camera and scan a partner’s number (or vice versa) to speed up the process. You can then mark the contact as verified using the button at the bottom of the screen.
This ensures that no man-in-the-middle attack takes place either. You know you are talking directly to a particular person.
If you can’t meet in person, the second best way is to share songs through another trusted platform. This could be an email address that only the other party can access, another messaging app, or even a phone or video call. Remember, any interaction where you can’t see the other person carries the risk of not being who he says he is.
This may seem like an exaggeration to friends, family and other casual employees. For journalists looking to verify the identity of a source or potential business partners discussing a top secret deal, it can provide that extra reassurance you need to chat in confidence.
RELATED: Verifying the identity of a signal contact (using the security number)
Use disappearing messages to avoid leaving a trail
Signal allows you to send self-destructing messages that will delete themselves after a period of time you choose. This is turned on on a per-conversation basis and applies to all messages in the chat. Once a message is seen, the self-destruct timer starts.
Launch Signal and tap a conversation to turn on Disappearing Messages. Tap your contact’s name at the top of the screen to view the chat settings. Turn on Disappearing messages and drag the slider to set the desired interval. You can choose a time of just five seconds and even a week.
This applies to messages you send and receive. Make sure to write down any important information or media stored in the chat before it disappears.
Note that the recipient of the message can always take a screenshot of the message (or take a photo of the screen of their device) before it disappears.
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Notices can violate your privacy
Depending on your chosen smartphone, your notifications can give away a lot of information about you. Many modern smartphones use facial recognition and fingerprint identification to quickly unlock your device. This allows your device to hide the content of incoming notifications until your identity is confirmed.
But this does not necessarily apply to all devices and some smartphone users will disable the setting. Messages you receive can be sensitive. Fortunately, both the Android and iPhone versions of Signal allow you to hide the content of notifications as an app setting.
To hide the content of notifications in Signal, launch the app and tap your profile icon in the top left corner of the screen. From here, tap on ‘Notifications’ followed by ‘View’ under Notification content. On the next screen you can make several choices:
- Name, content and actions: This is the default setting and does not hide anything in notifications.
- Name only: This hides the content of the message but shows who it came from.
- No name or content: This hides everything including the name and message (recommended).
Lock the Signal app and hide content in the app switcher
If you want an extra layer of security in addition to a system level passcode and biometric locks, consider locking the Signal app as well. Doing so will require you to unlock both devices and the app when you want to use it. This is especially helpful if you want to hand someone your phone over without worrying about getting them into your Signal account.
To lock Signal, launch the app and tap your user icon in the top left corner of the screen. Tap Privacy, then enable Screen lock and choose an appropriate timeout duration. This is how long Signal will allow before you need to unlock the app again.
Once that’s enabled, Signal can be unlocked using the same method you would use to unlock your device at the system level. This uses your device’s passcode or biometric information such as facial recognition and fingerprint identification.
While in the Privacy menu, you may also want to enable Screen Saver. This prevents information from being displayed when you switch apps. Unlike a thumbnail of the last call you had, you will now see a blue screen with the Signal logo.
Keep in mind that if you enable Screen Security on Android, you won’t be able to take screenshots of the app either.
RELATED: Protect signal messages with an access code
More security tweaks for iPhone users
Signal for iPhone has two additional settings that you may want to turn off for maximum privacy. The first is “Show Calls in Recents”, which allows calls made and received through Signal to appear in your iPhone’s main call list. This information is also uploaded to iCloud (if you are using it) and mirrored across devices.
The second is “Show in Suggestions”, which uses your Signal chats as suggested share locations when you tap the system-wide Share button. This can be useful if you’re primarily using Signal, but it will also reveal contact names outside of Signal.
If you want to turn off any of these settings, you can find them by launching Signal and tapping your user icon in the top left corner of the screen, followed by Privacy.
Remotely log out of paired devices
In addition to your main smartphone, you can connect up to five additional devices to Signal. If you are using Signal for security purposes, we recommend that you keep the app only on your smartphone. If you pair another device, you can immediately disconnect from that login from your main Signal device.
To do this, launch Signal and tap your user icon in the top left corner of the screen. Tap “Paired Devices” and find the device you want to unregister remotely. Swipe left, tap Unlink and confirm to complete the sign out.
Use signal anonymously? Register another number
Signal uses your phone number to identify you, which means you never need a password. This is useful, but what do you do if you want to speak to someone without revealing your phone number?
The answer is to get another number and sign up with that secondary phone number. You can get a “virtual” number from a service like Google Voice, or you can get a “burner” SIM card from a number that is not linked to your real identity. If you both want to use your existing phone number and an “anonymous” number, you need two phones.
Also take precautions to secure your smartphone
If you don’t keep your main smartphone safe, you can expose yourself to all kinds of problems. You can start by making sure your device is up to date. Depending on your device, do one of the following to install available updates on your operating system:
- iPhone: Launch your iPhone Settings app and go to General> Software Update.
- Android: Launch the Android system menu and go to About phone> System updates.
In addition, make sure your iPhone or Android device has a passcode and all relevant biometric authentication methods are set. Using your device without a passcode is essentially giving the keys to your email account and other accounts to potential attackers.
Finally, make sure not to leak information through software keyboards. On Android, you can launch Signal, tap your user icon in the top left corner, then go to Privacy> Incognito Keyboard and enable the feature.
For iPhone or iPad users, this is done through the Settings> General> Keyboard> System keyboards menu. If you don’t have any third-party keyboards installed, don’t worry about this. If so, you can choose to use the standard keyboard while typing in Signal or make sure that “Allow full access” is turned off under the keyboard settings.
Make sure contacts take security seriously too
If you use Signal to communicate privately, make sure everyone you talk to takes the same strict approach to privacy and security. Why not share this article with them?
Find out more about what makes Signal so great!
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