How to set a password for a memory card in Xiaomi Redmi smartphones: a step-by-step guide

Protecting data on a microSD card in Xiaomi Redmi smartphones is a pressing task for users who store sensitive files on it: photos, documents or backups. Unlike internal memory, removable drives are easier to lose or steal, and standard Android tools do not always offer reliable tools to block them. In this article, we will discuss all working ways to set a password to a memory card, from built-in MIUI functions to third-party applications and hardware encryption.

It is important to understand that not all methods are equally reliable. For example, passwords through the exFAT or FAT32 file system can be bypassed by simple formatting, while encryption (for example, through BitLocker To Go on a PC) provides protection at the military-grade level. We tested all methods on Redmi Note 10 Pro, Redmi 12 and POCO X5 Pro models - instructions are relevant for MIUI 13-15 (including hyper versions).

If you use your memory card as an internal drive (Adoptable Storage feature), some methods will not be available – we will warn you about this separately in each section. Also note that after you set a password, access to files from other devices (for example, through a card reader on a PC) may be limited.

1.Memory card protection through built-in MIUI features

Xiaomi has added an option to lock external drives to its MIUI shell, but it doesn’t work on all firmware versions.This method is suitable for cards formatted as portable (not as internal memory). Check the MIUI version in the Settings menu → About Phone → MIUI version – a feature available starting with MIUI 12.5.

To set the password:

1. Open the Files app (folder icon).
2. Go to Device and select your memory card (usually indicated as SD-card).
3. Slip on the three dots in the upper right corner and select Settings.
4. Find the item Protect memory card or Lock SD-Cards (the name may be different).
5. Create. PIN-code or pattern lock. Length PIN — 4 to 16 characters.

Once activated, a password will be requested every time you connect the card to your phone, and note that this method does not encrypt data, but only blocks access through MIUI. You can read the card on another device without a password if you connect it through a card reader.

⚠️ Warning: If you reset your phone to factory settings, the memory card password will be reset automatically. Create a backup of important files before resetting.

2.Use of third-party applications to block

If you don't have built-in protection in your version of MIUI, you can use third-party utilities. We tested 5 popular apps and selected the two most reliable ones: AppLock (from DoMobile Lab) and Folder Lock. Both support blocking access to files on the memory card, but work differently:

• 🔒 AppLock: blocks access to applications, including Files, but does not encrypt the files themselves.
• 📁 Folder Lock: creates an encrypted container on a memory card where you can move sensitive files.
• 🛡️ Vaulty: Hiding files and making them inaccessible without a password, but can conflict with MIUI on some Redmi models.

Instructions for Folder Lock (recommended for maximum protection):

1. Install the app from Google Play.
2. Open it and create a master password (we recommend at least 8 characters with numbers and letters).
3. Go to the Lock Files section and select files/folders on the memory card.
4. Press Lock – files will be moved to a protected partition and encrypted.

The advantage of this method is that even if the card is removed and connected to another device, the files in the encrypted container will remain inaccessible, and the disadvantage is that you will have to manually manage which files to protect.

3. Encrypting a memory card via a PC (the most reliable way)

If you need full-fledged AES-256 encryption, the best option is to use Windows or macOS utilities. This method is suitable for users who often connect the card to a computer. We recommend VeraCrypt (free) or BitLocker To Go (built into Windows Pro).

Instructions for BitLocker To Go:

1. Connect the memory card to the PC through the card reader.
2. Open Explorer, right-click on the card drive and select Enable BitLocker.
3. Set a password (minimum 8 characters) or use a smart card.
4. Save the recovery key to the file or print it out.
5. Select encryption mode: Only occupied space (faster) or the entire drive (more reliable).
6. Wait for the process to be completed (it can take up to an hour for 128+GB cards).

Once encrypted, the card will only be connected to BitLocker-enabled devices (Windows) or through special Android apps (such as Paragon ExFAT/NTFS), and Xiaomi smartphones will have to manually unlock the encrypted card each time they connect.

⚠️ Note: If you encrypt your card through BitLocker and forget your password, it will be impossible to recover data without the recovery key. Store it in a safe place (for example, in Google Drive or on paper).

4. Features for cards used as internal memory

If you have configured the memory card as an internal drive (via Settings) → Memory. → SD-map → Format as internal, most security methods will become unavailable, which is because Android integrates the card into the file system. ext4 or f2fs, It becomes inseparable from the main memory.

In this case, there are two options:

• 🔄 Format the map back to portable mode (lost all data!). After that, you can use any methods from this article.
• 🔐 Encrypt the entire phone through Settings → Security → Encrypting the phone, which will protect the memory card, but slow the device down by 10 to 15%.

To check the current map mode, go to Settings → Memory. If the card name has internal memory, it is integrated into the system.

5. Alternative ways to protect data on the map

If setting a password seems difficult, consider alternative methods:

• 📱 Hidden folders: Create a folder with a name that starts at a point (such as.secret) – it will not appear in a standard Explorer. → Settings → Show hidden files.
• ☁️ Cloud backups: upload important files to Google Drive or Mi Cloud and delete them from the card.
• 🔗 Symbolic links: transfer files to the internal memory and create links to them on the map (root or root is required). ADB).

For hidden folders, you can use the File Hide Expert app, which adds an additional layer of protection, a password to access hidden data, but this method does not protect against power users who know how to turn on the display of hidden files.

💡

If you move files between your memory card and your PC frequently, use the cloud (Google Drive, OneDrive) with Files on Demand, which saves space on the map by only saving access to files when you connect to the Internet.

6. Frequent mistakes and how to avoid them

When setting up a password on a memory card, Xiaomi Redmi users often face typical problems:

• 🔌 "The card is not determined after "encryption": the cause may be incompatibility of the file system. For example, BitLocker works only with the help of the file system. NTFS Or exFAT, and MIUI by default formatting the cards in FAT32.
• 🔑 "Forgot the password from Folder Lock: in this case, you can only restore access through an email linked to the application. If you did not save a backup, the data will be lost.
• ⚡ "Phone brakes after encryption: 'normal for weaker models' (Redmi) 9A, Try disabling encryption or using a card in a class at least lower A2.

To avoid mistakes:

1. Before encryption, check the file system of the card through Settings → Memory. → SD-map → Format.
2. Do not use cards larger than 256GB with FAT32 – they will be broken into pieces, which can break encryption.
3. For models with Qualcomm Snapdragon (like Redmi Note 11 Pro), VeraCrypt is better optimized for these processors.

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The most reliable method is encryption via VeraCrypt/BitLocker on a PC, but it requires additional actions every time you connect the card to your phone. Folder Lock or built-in MIUI lock (if available) is suitable for everyday use.

FAQ: Answers to Frequent Questions