Smartphones today store a huge amount of sensitive information, from instant messaging to photos and banking apps. Xiaomi device owners often face the need to restrict access to certain programs to protect their data from prying eyes. The Redmi Note 9 features a MIUI shell that provides built-in and powerful digital security tools without installing third-party software.
The procedure for installing protection is quite simple, but has its own nuances depending on the version of the Android operating system and the MIUI. Users have a variety of methods available, including graphic keys, digital codes and biometric identification. In this article, we will discuss all the ways of blocking in detail so that you can choose the most convenient option for your use case.
It's important to understand that setting your privacy right is not just about installing code, but also understanding how Xiaomi's security system works. A good configuration will allow you to hide not only the launch of apps, but also the notifications from them, ensuring maximum privacy. Let's move on to the practical steps of configuring your device.
MIUI's built-in protections
MIUI offers a native feature called Application Protection, which is the most reliable and energy-efficient way to lock, integrated deep into the system, which ensures stable operation without affecting the autonomy of the Redmi Note 9. To activate the function, you need to go to the security settings, where the system will prompt you to create a unique password other than the unlock password of the screen.
When you first start, you will be asked to select the type of lock: a pattern lock, PIN-A pattern lock is often considered more convenient for frequent use, as it is easier to enter with one hand, but from a security perspective, complex numerical combinations or letter passwords provide a higher level of protection against selection.
⚠️ Note: Do not use simple combinations like “1234” or geometric shapes like “G” as they are easily reproduced by screen traces or by observation.
Once you have set your primary password, the system will suggest you link your Mi Account, a critical step to restore access to blocked applications in case you forget the security code. Without an associated account, it may be impossible to restore access to data, so it is not recommended to ignore this step.
Then you'll see a list of all the installed software, and you'll have to manually select the apps you want to protect, which can be WhatsApp, Telegram, a gallery, or even phone settings, and then you'll only open each app after you've signed in.
Set up biometric unlocking
With a side-facing fingerprint scanner, Redmi Note 9 owners can unlock their applications with a fingerprint, which makes it much faster to access secure data and eliminates the need to enter a password every time. MIUI biometrics work quickly and reliably using modern recognition algorithms.
To activate this feature, you need to go to the Application Protection menu and find the biometric settings. Here you can turn on the option “Unlock fingerprint”. The system will require you to confirm the action with the current security password to make sure that the access is made by the owner of the device. After activation, when you try to open the blocked application, the smartphone will expect to touch the scanner.
It's worth noting that biometric unlocking has its limitations, for example, after a device is rebooted or if a scan is unsuccessful, the system will still require a master password, a standard Android security measure that cannot be circumvented software.
Face unlocking is also available, although it is less safe than a fingerprint because it uses a conventional front-facing camera without infrared sensors, but it is effective and convenient in everyday use for basic protection against casual gaze.
☑️ Security setting
Use of hidden space (Second Space)
One of Xiaomi's unique features is the Second Space feature, which is a fully isolated environment inside your smartphone that works as a single user, and in this space you can install copies of apps, store files, and take photos that are completely inaccessible from your main profile.
To activate the Second Space, you need to go to the settings and select the appropriate item, and the system will suggest that you configure the entrance to this space: this can be a separate fingerprint or a special pattern lock, for example, unlocking one finger opens the main profile, and the other one opens the hidden one.
Inside the Second Space, you can install the same messengers as the main profile and log in to them under different accounts, ideal for separating work and personal life or creating a cache that an outsider may not even know exists.
Switching between spaces is instantaneous and doesn’t require rebooting, but remember that data in two spaces takes up space on the same physical drive, so keep an eye out for free memory on your Redmi Note 9.
How do you remove the second space?
Blocking access to settings and system functions
In addition to third-party applications, it is often necessary to restrict access to the system settings of the smartphone itself. An attacker or a curious child can change network settings, disable geolocation or reset security settings. In MIUI you can even put a password on the Settings icon.
The process is similar to blocking regular applications: you select Settings from a list of protected programs, and then no system option changes without your knowledge, which is especially useful if you give someone a phone to call or play, but you are afraid that important settings will be changed.
Also worth noting is the Guest Mode feature, which allows you to temporarily limit the functionality of the device, unlike full application lock, guest mode creates a temporary session with limited access to contacts and call history.
The combination of application locking and system setting limitations creates layered protection. The Redmi Note 9 has enough performance to ensure that such background permission verification processes do not affect the speed of the interface.
Comparison of data protection methods
The choice of security depends on your priorities: speed of access or maximum stealth. Standard locking applications are most convenient for daily use, while Second Space is ideal for storing truly sensitive information. Understanding the differences will help you build the optimal security strategy.
Below is a table comparing the main characteristics of the various protection methods available on the Xiaomi Redmi Note 9.
| Protection method | Level of secrecy | Speed of access | Difficulty setting up |
|---|---|---|---|
| Application protection | Average (list seen) | Tall. | Low. |
| Second space | High (complete isolation) | Medium (entrance required) | Medium |
| Guest mode | Low (temporary) | Tall. | Low. |
| Blocking notifications | Average (hidden text) | Instant. | Low. |
As you can see from the table, for most users, the best option is to combine Application Protection with the option to hide the content of notifications enabled, balancing between convenience and security.
If you need to hide the very fact of the presence of certain applications (for example, banking or dating), then the only correct solution is to use the Second Space or third-party launchers with the hide function.
Hiding notifications and content on the lock screen
Even if the application is password protected, the text of the incoming message can be seen on the lock screen. To completely protect yourself from shoulder-like views, you need to configure the notification display. MIUI has flexible settings for each application installed.
Go to the notification settings and select the app you want, and you can turn off the display on the lock screen or select the option “Hide content”, in which case you will only see the name of the application and the number of messages, but not the text until you unlock the device.
Also in the Application Protection settings, there is a separate “Hide the contents of notifications” switch, which when activated, even if the phone is unlocked, the text of the message in the notification curtain will be replaced with asterisks or dots until the app itself opens.
This feature is especially relevant in public places or at work, and it prevents information from leaking through pop-ups that may appear at the most inopportune moment.