Modern smartphones Xiaomi and Redmi offer users advanced methods of personal data protection, among which biometrics occupies a leading position. Using a fingerprint allows you not only to instantly unlock the device, but also to confirm payments in Google Pay, Mi Pay, and hide confidential files in a special storage. Many owners of gadgets are limited to basic settings, without even knowing about the hidden functions and subtleties of calibration of the sensor.
In this detailed guide, we’ll take a look at how to properly activate a fingerprint sensor, add multiple fingerprints to improve recognition accuracy, and take advantage of the additional security features of a MIUI or HyperOS system. Proper setup during the initial use phase will save you from problems with false access denials in the future.
It should be noted that the location of the scanner can vary depending on the model: in budget devices, it is often combined with a power button on the side edge, while in flagship models it is built directly under the screen. Regardless of the type of sensor, the software operation remains similar, requiring only careful attention to the scanning process.
Location of sensors and sensor types in Xiaomi devices
Before you start setting up, it is important to determine the type of sensor you have installed in your smartphone, as this affects the reaction speed and method of data entry. Most modern mid- and flagship models use a subscreen optical scanner that reads the pattern of papillary lines through light radiation, such devices require a tighter finger press to the display to activate.
More affordable models, such as the Redmi Note series or the Redmi letter-coded series, often feature classic physical buttons. They can be located on the back of the case or integrated into the side-on switch. Physical buttons tend to have high speed and haptic return, which is convenient in the dark.
Regardless of the design, the Android software interface in the manufacturer’s shell is standardized. The user needs to access the security settings menu, where the initial initialization of the equipment occurs. If the sensor has stopped responding, the first thing to check for the absence of protective films for scanning areas or contamination.
Primary setting and adding a fingerprint
The process of recording biometric data is a fundamental step, the quality of which depends on the further speed of unlocking. First, you need to go to the Settings menu, then select the Passwords and Security section and click on Unlock by fingerprint. The system will request the input of the current PIN-code or pattern lock to confirm administrator rights.
Once activated, a window will appear with instructions to put your finger on the sensor, so it's important not just to touch the surface, but to slightly change the angle of inclination, grabbing the edges of the pad, and this creates a three-dimensional fingerprint map, which is critical for successful identification in different environments.
☑️ Checklist of correct registration
The system will progressively fill in the scale, displaying the percentage of execution, it is recommended to bring the fill up to 100%, even if the phone suggests to complete the setting earlier.
There may be pauses in the recording process to calibrate, and if you feel that the sensor is sluggish, interrupt the process and start over with a first wipe, and the cleanliness of the sensor is the key to its correct operation, because the fatty traces can distort the optical reading.
Advanced Features: Second Fingerprint and Hiding Files
One of the most useful but rarely used features of the Xiaomi ecosystem is the ability to add a second, “fake” fingerprint, which is designed for situations where you can be forced to unlock your phone. If you attach a finger designated as “second”, the smartphone will unlock, but will only show the main desktop with no hidden applications and files.
To configure this function, you need to find Add a fingerprint and register a finger in the fingerprint menu, which will be used for emergency unlocking. In the security settings, you should activate the option Hidden Content or Second Space, linking it to the new biometric key.
In addition, the system allows you to hide individual photos and videos in the gallery, and once the hidden album function is activated, access to it will only be possible after you enter a password or attach your thumb, which creates an additional level of privacy for the personal media library.
How does the data hiding algorithm work?
Also worth mentioning is the application unlock feature: You can configure access to instant messengers or banking clients (Sberbank Online, Tinkoff) only through biometrics. This is done through the Settings menu → Applications → Application Protection, where you select the desired software and authorization method.
Use of fingerprint for payments and authorization
Biometrics makes it much easier to make purchases online and in stores, and unlike long card passwords, transaction confirmation takes a fraction of a second. NFC-payments where a fingerprint is chosen as the confirmation method.
When paying in a store, you need to bring your phone to the terminal and, without removing it, put your finger on the scanner. If the phone is on the table, payment will not pass without biometric confirmation, which is an important measure of protection against theft of funds in case of loss of the device.
💡
For contactless payment NFC-The module is usually located at the top of the back panel. Try to attach this area to the terminal, not the center of the housing.
Many apps, like WhatsApp, Telegram, or bank clients, support fingerprint login, which eliminates the need to enter a PIN every time, but it’s worth remembering that once the device is rebooted, the first sign-in to the application always requires a primary password.
The table below compares the features of using the fingerprint in different scenarios on Xiaomi devices:
| Use case scenario | Internet is required | Acting after rebooting | Level of security |
|---|---|---|---|
| Screen unlocking | No. | No (password needed) | High-pitched |
| Payment in the Store (NFC) | No. | No (password needed) | Very tall. |
| Entrance to the banking application | Yeah (for the appa job) | No (password needed) | High-pitched |
| Authorization in Mi Account | Yes. | No (password needed) | Medium. |
💡
Biometric data is stored in a secure isolated module (TEE) of the processor and is never transferred to Xiaomi or Google servers, which guarantees its privacy.
Problems with recognition and methods of their solution
Despite the high accuracy of modern sensors, users may experience situations where the phone no longer recognizes the owner, often due to changes in the skin of the hands: dryness, moisture, cream or mechanical damage (cuts, calluses) can temporarily disrupt the reading, in which case the system automatically prompts you to enter a password.
If the problems are permanent, recalibration may be required, remove the old fingerprint from memory and register it again, paying special attention to the edges of the finger, and add the same finger twice under different names (for example, "Finger 1" and "Finger 1 copy"), which will increase the database for comparison.
The effects of protective glasses can also be ignored: glass that is too thick or poor can block ultrasonic or optical signals. If you recently changed your screen protection and notice a deterioration in the scanner, try removing it for inspection.
In rare cases, the problem is a software failure: Rebooting a device or upgrading to the latest version of MIUI often fixes driver errors, and if nothing helps, there may be a hardware malfunction of the plume or the module itself.
Security and technology limitations
Using biometrics raises questions about how secure such data is to be stored. As mentioned, Xiaomi uses the TEE (Trusted Execution Environment) standard, which means that the mathematical representation of your fingerprint is stored in encrypted form in a separate sector of memory, which is not accessible by the operating system, applications or even the manufacturer itself when remotely accessed.
However, there are physical limitations. A fingerprint cannot be “changed” as a password if its data is somehow compromised (although it is extremely difficult to steal a hash from a phone in practice), so for mission-critical operations, such as logging into a cloud storage from a new device, the system will still require the primary password.
⚠️ Note: Do not use facial unlock in conjunction with a fingerprint if you have twins or relatives with very similar appearances, although this is less relevant for fingerprints, as the patterns are unique even in identical twins.
Legal aspects are also important to remember: in some jurisdictions, the police can force you to unlock your phone with a fingerprint, but they can’t force you to give your password (as the password is the content of your mind).
Additional settings and personalization
HyperOS shell and new versions of MIUI allow you to adjust the behavior of the scanner. For example, you can change the vibration when you try to enter successfully or unsuccessfully. This helps you tactilely feel the unlock status without looking at the screen. The settings are in the section Sounds and vibration → Vibration when touching.
For users with underscreen scanners, you can set up the unlock animations, you can choose the style of effect that you get when you put your finger on, it doesn't affect speed, but it adds aesthetics to the process, and some design themes can replace standard animation with your own.
If you use a case with thick sides, make sure it does not block access to the side scanner, otherwise you will have to remove the case every time or press the button hard, which can lead to mechanical wear.
⚠️ Note: When registering a fingerprint, try not to use a finger that you often wet or stain during the day (for example, the right-handed thumb of a right-handed person) as the only key.
Regular cleaning of the sensor with soft dry fabric will prolong its life and maintain a high response rate. Avoid the use of aggressive chemicals that can damage the oleophobic coating or optical element.