How to Hide Sensitive Information From Notifications
Last week, it was revealed that the FBI had accessed deleted Signal messages on a defendant’s iPhone , despite the user having completely deleted the app from their device. It’s not that the FBI was able to find the messages themselves; rather, it was discovered that they were able to extract incoming Signal messages from the defendant’s push notification database. If you, like most people, weren’t aware that devices like the iPhone have such a push notification database and that it can be used to recover deleted messages, fortunately, there’s a simple way to protect yourself and ensure that no one can access sensitive information from this space on your iPhone or any other device that receives sensitive notifications.
It’s unclear how the push notification database works and whether information about them is deleted when you clear notifications. However, we can get some insight from a blog post by the Objective See Foundation (albeit from 2018) that highlighted an issue with Signal messages on Mac. The post states, “In short, anything that appears as a notification (yes, including ‘disappearing’ Signal messages) in macOS Notification Center is recorded by the operating system.” It appears that a recent FBI investigation exploited a similar loophole to obtain data from iOS notifications.
So, how do you protect yourself? The safest way is to disable notifications completely, which will prevent any information from being stored in this database, but for most people, this is impractical. Most of us want to be alerted to new emails, messages, or important app updates. However, you can prevent your device from displaying message content in notifications, preventing this information from appearing in the database. In this case, every notification you receive will look something like “You have a new message” rather than “Pranay Parab: My Netflix password – Lifehacker.” Again, it’s unclear how this database works and which platforms share the same database as the iPhone, but for privacy and security purposes, I’ve listed the steps for most major device platforms below:
Protect sensitive notifications on iPhone
Your iPhone has the ability to hide message content from notifications for all apps. You can enable this feature by going to Settings > Notifications > Show Previews and selecting Never . You can also disable notification previews for specific apps. To do this, go to Settings > Notifications , scroll down, and tap the name of the app for which you want to hide notification previews. Select Show Previews > Never , and repeat this step for all other apps for which you want to hide notifications.
Clearing Notification Database Information on Mac
On your Mac, you can also hide notification previews globally or for individual apps. First, go to System Preferences > Notifications . Click the drop-down menu next to “Show Previews” and select “Never.” This will disable notification previews completely. Alternatively, you can scroll down the list, select any app, and click “Show Previews” > “Never” to disable previews for individual apps.
If you want to remove notifications from your Mac’s database, you can install the free app AuRevoir , developed by The Objective See Foundation based on their findings. It allows you to view and delete all information stored in your Mac’s notification database. You can click “View Messages” to see the stored data, then “Delete Messages” to remove them from your Mac.
Keep sensitive information out of Android notifications.
While Android offers several ways to hide notification previews on the lock screen , there aren’t many options for disabling them when unlocking your phone. It’s easier to disable notification previews in each app’s settings page individually than to search for a toggle that works across all Android versions.
To disable lock screen notifications, go to Settings > Notifications > Lock screen notifications and disable “Show sensitive information.” You can also enable “Hide silent notifications in the status bar” and disable “Show silent notifications.” There are several more detailed settings under Settings > Notifications > App notifications , so be sure to check them out as well. These settings may differ on your Android phone due to manufacturer settings.
Clear notification information in Windows
Unfortunately, Windows doesn’t have a global setting to disable notification previews, but you can hide previews on the lock screen. To disable notification previews in Windows, open the Start menu and click the gear icon next to the power button. This will open the Settings app. Go to System > Notifications > Notifications . Disable “Show notifications on the lock screen.” Then, scroll down and select each app for which you want to hide previews, and enable “Hide content when notifications appear on the lock screen.”
Additionally, to disable previews, you’ll have to rely on notification settings in individual apps. I’ve listed a few popular options below.
Hide sensitive information from notifications in popular instant messaging apps.
Popular messaging apps allow you to disable notification previews through the app settings. This is just as effective as using your device’s system settings to disable notification previews, but I’m mentioning it here in case your operating system doesn’t allow you to easily disable notification previews:
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In WhatsApp, you can go to the app settings, tap Notifications , and turn off the Show Preview option .
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If you use Signal, tap your profile icon in the upper left corner and go to Settings > Notifications . Select Show under Notification Content. On the next page, the safest option is to select No Name or Content .
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You can also do this in Telegram’s settings. Go to “Notifications & Sounds” > “Private Chats” and disable message previews . You can do the same on the “Group Chats” page in the notification settings.