Modern smartphones store a colossal amount of personal information, from bank secrecy to private correspondence. Owners of popular models, such as Samsung Galaxy A51, are often faced with the need to restrict access to certain apps, even if the phone itself is unlocked. This is especially true when children use the gadget or when the device temporarily falls into the hands of colleagues.
Unfortunately, in the standard shell One UI from Samsung there is no single “Block all applications” button in the usual sense. However, the company offers more advanced and secure solutions, such as Knox folder (Secure Folder), as well as the ability to use third-party software. The choice of method depends on how deeply you want to integrate protection into the system.
In this article we will examine in detail both ways: using a built-in secure container and installing specialized blockers. You will learn how to set up biometric protection, what pitfalls each method has, and how to ensure that your data remains inaccessible to prying eyes.
Built-in protection via Secure Folder on Samsung A51
The most reliable way to hide and protect applications on devices Samsung is to use the function Secure Folder. This is an isolated space in the phone's memory that works as a separate profile. Apps moved here require additional authentication to launch, regardless of whether the main screen is unlocked.
To activate this feature, you must go to system settings. Find the section Biometrics and Security and select item Knox Folder. The system will prompt you to accept the terms of use and log into your account Samsung Account. This is a mandatory requirement, since the data is encrypted with reference to your account.
After the initial setup, you will be asked to select a lock type. You can use the same PIN code pattern key as to unlock the screen, or set a completely new one. For owners Galaxy A51 unlocking via fingerprint is also available, which significantly speeds up access to protected data.
⚠️ Attention: Do not set the same password for unlocking the screen and for the Knox Folder if you are afraid that someone might spy on the input code. Different combinations increase the level of security.
When the folder is created, a new icon will appear on the desktop. Inside it you can add any installed applications. It is important to understand that this will create a copy of them. For example, you will have a normal one Instagram on the main screen and a protected one Instagram inside a folder with a separate login.
Use the "Hide Knox Folder" function in the settings of the folder itself so that the protected storage icon disappears from the desktop. You can return it through the quick settings panel.
Using third-party application blockers
If the isolated folder method does not suit you due to duplication of apps or memory consumption, you can turn to third-party solutions. The store Google Play presents many utilities, such as AppLockthat impose a layer of protection on top of any installed apps.
The principle of operation of such applications is based on granting them special permissions. After installation, the blocker will request the right to on top of other windows. This is a critical setting that allows the app to intercept the opening of other applications and require a password before launching.
The setup process is usually intuitive. You select from the list the apps that you want to protect and set a master password. Some advanced blockers allow you to take a photo of the front camera when an attempt to enter a code is unsuccessful, which helps identify the attacker.
However, it is worth considering that third-party applications can consume more battery resources and sometimes conflict with system updates Android. In addition, they do not provide the same level of data encryption as the native solution from Samsung.
☑️ Checking blocker settings
Setting up biometric authentication for access
Entering a password every time can be tiresome, therefore Samsung Galaxy A51 suggests using biometrics. The fingerprint scanner in this model is located on the side, in the power button, which makes unlocking very convenient.
To activate fingerprint entry into secure areas, you must first register your fingers in the main security settings. Then, inside the settings Knox folders or the blocker application, you need to turn on the appropriate toggle switch.
The system will remember your fingerprint and will let you into the protected space instantly. However, the system periodically (usually after rebooting the device) will require you to enter the main Digital code or graphic key for security purposes.
| Protection type | Security level | Convenience | Impact on the battery |
|---|---|---|---|
| Knox folder | High (hardware) | Medium | Minimum |
| Third-party AppLock | Medium (software) | High | Medium |
| Pattern key | Low (easy to spy) | Low | None |
| Fingerprint | High | Very high | Minimal |
Using biometrics does not replace the need to remember the backup password. If the scanner is dirty or your finger is damaged, only the code can save the situation. Therefore, always keep a combination of numbers in mind.
Biometrics is a convenience, but a digital password remains the only way to restore access in case of sensor failures.
Hide the application icon in the general menu
In addition to setting a password, Samsung A51 you can completely hide application icon from the general menu, leaving it accessible only through search or a protected folder. This adds another level of privacy, since a stranger will not even see that the app is installed.
To do this, go to the main screen settings. Press and hold an empty space on the desktop and select Settings. In the menu that opens, find the section Hide applications. Here you can tick the apps that you want to hide from view.
After applying the settings, the icons will disappear. To launch a hidden application, you will have to use the search on your phone or enter its name manually. If the application is inside Secure Folder, its icon in the main menu disappears automatically when you move it.
⚠️ Attention: Hiding the icon does not delete the application. It continues to run in the background and receive notifications unless configured otherwise.
This feature is especially useful for apps that you do not want to remove, but prefer not to advertise their presence on the device. The combination of hiding and password gives the maximum effect of stealth.
How to find a hidden application?
To return hidden applications or launch them, open the all applications menu, click on the three dots in the corner (or the magnifying glass icon) and enter the exact name of the app. It will appear in the search results, even if the icon is not on the screen.
What to do if you forget the password for a protected folder
The situation when a user forgets the access code to Secure Folderis not uncommon. Fortunately, the ecosystem Samsung provides a recovery mechanism, but only if you have configured it in advance.
When setting up the folder for the first time, the system strongly suggested linking an account Samsung. If you agree, then if you enter your password incorrectly multiple times, the “Forgot your password?” button will appear on the screen. By clicking on it, you can reset the protection through verification in your account.
If the account has not been linked or you do not remember the data from it, unfortunately, it is impossible to restore access to the data inside the folder. The only way out is a complete reset of the content Knox folders, which will lead to the permanent loss of all files and application settings inside it.
This is why security experts recommend enabling cloud synchronization for important data inside a protected container. This will allow you to save contacts and photos even if you lose access to the security device itself.
⚠️ Attention: Resetting your password through your Samsung account will delete all data inside the Knox Folder. Make sure you have backup copies of important files before this procedure.
Limitations and features of working on Android 11-14
With the release of new versions of the operating system AndroidGoogle's security policy is becoming stricter. This affects how app blockers work. On versions Android 11, 12 and later, access to some system functions for third-party apps is limited.
For example, some blockers may not work correctly with system settings or instant messengers that use their own lock screens. In such cases, the application may open for a split second before the password request appears.
The built-in solution from Samsung is free of these problems, since it has the rights of a system application. However, it can also change its interface with each shell update One UI. Menu items may move, but the essence of the function remains unchanged.
Users should regularly check for firmware updates. Sometimes security patches fix vulnerabilities that could theoretically allow you to bypass application protection.
Before a major Android update, make sure you remember the password for the Knox Folder and your Samsung account is active to avoid access problems after a reboot.
Frequently asked questions (FAQ)
Is it possible to set a password to specific messages in Samsung Messages?
No, the standard Messages application does not allow you to set a password for individual dialogs. However, you can move the entire Messages app inside Knox folders. Then authentication will be required to enter the conversation, but regular SMS will remain visible in the main folder unless you delete them from there.
Does using AppLock affect the speed of the Samsung A51?
Minimal impact is possible, especially when running protected applications, since the system you need to check access rights. On the processor Exynos 9611installed in the A51, modern optimized blockers work almost unnoticed by the user.
Will a person see a photo in the gallery if I put a password on the Gallery application?
If you block the standard Gallery application through a third-party blocker, the person will not be able to open it. However, he will still be able to see photo thumbnails in widgets or through the file manager. For complete secrecy, it is better to move the photo to Secure Folder.
What will happen to notifications from blocked applications?
By default, notifications can be displayed on the lock screen or in the curtain, revealing the essence of the message. In the settings of most blockers there is a function “Hide the contents of notifications”. Activate it so that only the application name is displayed on the screen without the message text.
Is it possible to set different passwords for different applications?
Standard Knox folder uses a single password for all applications within it. Third-party applications like AppLock often allow you to set individual passwords or fingerprints for each app separately, which gives more flexible security settings.