The modern smartphone stores a huge amount of personal information, from correspondence in messengers to photos and banking applications. Owners of budget but functional devices such as the Xiaomi Redmi 9 often wonder about the additional protection of their data from prying eyes. Standard screen locking is sometimes not enough, especially if the phone is used by children or if the gadget has to borrow colleagues.
Fortunately, the MIUI shell on which the Android operating system is based in these smartphones offers powerful built-in tools to restrict access. You do not have to download dubious programs from third-party sources, since all the necessary functions are already deeply integrated into the system. In this article, we will discuss in detail how to configure passwords for specific applications to ensure maximum privacy.
The process of installing security is quite simple, but it has its own nuances depending on the firmware version. We will discuss the standard method through security settings, and also touch on the topic of creating hidden space for sensitive data. Understanding these mechanisms will allow you to feel more confident when using the device in any situation.
Preparing a security system before setting passwords
Before you start blocking individual programs directly, you need to make sure that the system has a basic level of protection set up. Security in the Xiaomi ecosystem is built on linking to an account and setting a master password. If you just reset your device or use it without restrictions, the system may require you to create an access code when you first try to protect the application.
It is recommended to come up with a strong pattern lock or digital code that will be different from the screen unlock code, which will create an additional barrier for attackers, and make sure that your Mi Account is active and tied to the device, as this may be necessary to restore access in case of forgetting the password.
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Use a complex pattern lock of 6-7 dots instead of a simple digital code – it is much harder to peek from the side or guess from the fingerprints on the screen.
It is important to understand that the application protection setting affects the system components of MIUI Security. So before you start manipulating, make sure that you have access to the main settings menu and administrative user rights (which the owner has by default).
Step-by-step: activation of application blocking
The main tool for access configuration is in the standard system application Security. It is not a third-party utility, but an integrated shell component that has deep permissions to access the system. To start, look for an icon on your desktop or in the Tools folder called Security (green shield) and run it.
Once you open the app, scroll down to the Privacy or Security section. Here you need to find Application Protection (some firmware versions may call it Application Lock). When you first start, the system will ask you to come up with a password. You can choose the format: graphical pattern, 4-digit or 6-digit numeric code.
☑️ Setting up application protection
Once you set the password, you will be prompted to link your Xiaomi account. It is strongly recommended to do so to be able to restore access if the primary password is forgotten. Then a list of all installed programs will open. Just switch the sliders in front of those applications that you want to hide from outsiders (for example, WhatsApp, Gallery, Contacts).
⚠️ Note: If you forget the application protection password and do not link your account for recovery, the only way to return access to data is to completely reset the device to factory settings, which will lead to the removal of all information.
Now, every time you run a selected application, the system will request a password or fingerprint scan (if activated), which ensures that even an unlocked phone cannot be used to access secure data.
Set up biometric unlocking for quick access
Constantly entering a pattern lock or digital code can be annoying, especially if you access a blocked app dozens of times a day. Xiaomi Redmi 9 features a fingerprint scanner located on the back and a face unlock module. These tools can be used to instantly access secure programs.
To activate this feature, go back to the Application Protection menu and click on the gear icon in the upper right corner of the screen. Here you will see the option "Unlock fingerprint" or "Face ID." Activate the desired switch. The system will require you to confirm your main application protection password to make changes.
Using biometrics makes it much faster to log in, so you just tap the sensor or look at the screen and the app opens without entering the code, but remember that biometrics are stored in a secure sector of the processor's memory and not transmitted to the company's servers, which provides a high level of privacy.
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Biometric unlocking in the application protection menu works independently of the main screen unlock, providing dual access control to the data.
If the fingerprint scanner fails the first time (for example, because of wet hands), the system will automatically prompt you to enter a backup password, which is a standard security behavior designed to prevent unauthorized access in unusual situations.
Use the Hidden Space function for maximum privacy
For users who don’t just want to block an app, but want to completely hide it on their device, MIUI has a “Second Space” feature that creates an isolated environment that looks like a separate, clean desktop without your personal data.
To activate this mode, go to Settings → Additional Settings → Second Space. By clicking “Enable”, you will start the process of creating a new profile. You will be asked to set a separate password or fingerprint to enter this space, for example, the thumbprint input opens the main desktop, and the index fingerprint input opens the hidden space.
Inside the hidden space, you can install copies of any applications from the main profile or download new ones. All data is stored separately. To an outside observer, your device will look completely empty or contain only standard system applications.
| Function | Application protection | Hidden space | Guest mode |
|---|---|---|---|
| Visibility of the icon | You can see it. | Hidden completely. | Seen, but empty. |
| Password required | At launch. | When entering profile | When switching |
| Data isolation | Partial | Complete. | Complete. |
| Accessibility | High. | Average. | High. |
Switching between the main and hidden spaces is fast, but requires remembering different combinations of logins, ideal for storing compromising photos or documents that should not be visible even in the list of recently launched main profile apps.
What happens to notifications in a hidden space?
Access management and elimination of system errors
When using secure applications, users may find themselves in a situation where the application stops running or the lock is not working correctly, often due to system updates or conflicts of Android versions, in which case it is useful to know how to manage the list of protected programs.
You can always temporarily turn off protection for a particular application without removing the shared password. Go to the security settings, find the application you want, and uncheck the box. Also, the settings (Security settings) have a feature called Protect App Installation. If it's enabled, no one can install new programs without your password, which is a great barrier for kids.
Sometimes users forget which apps they have blocked. The list is always available in the Security menu. If the application crashes when you try to enter a password, try clearing the cache of the Security system application through the memory management menu, but do not delete its data so as not to bring down the password settings.
⚠️ Note: When you delete an application that has a password, the lock settings for it are reset. However, if you reinstall the application, you will have to add it to the protected list again.
Regularly check the relevance of the MIUI shell version. Developers periodically release security patches that may affect the application protection module. Updating to the latest available version often solves problems with unstable operation of biometric sensors in protected mode.
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If you plan to sell your phone or give it away for repair, be sure to delete all passwords and log out of Mi Account, as the app protection feature can lock the device even after a reset if activation lock is enabled.