Secure File/Folder Lock & Unlock (Batch + 7-Zip)

Overview

This batch script allows you to encrypt or decrypt files and folders using 7-Zip.
It supports custom or default passwords and automatically deletes the original after encryption or decryption for security.

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Encryption Details

When using:

-p (password)  +  -mhe (encrypt headers)

7-Zip applies:

• AES-256 encryption
• CBC (Cipher Block Chaining) mode
• SHA-256 key derivation from your password

✅ Strong, modern encryption
⚠ Weak passwords (e.g., 1234) can still be brute-forced.
📂 The .7z format is open and can be decrypted with the correct password using any compatible tool.

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Example Commands

Encrypt:

7z a -pMySecret123 -mhe locked.7z Secret.txt

• 7z → Runs 7-Zip
• a → Add to archive
• -pMySecret123 → Sets password (replace with your own)
• -mhe → Encrypts file names
• locked.7z → Output archive
• Secret.txt → File to encrypt

Delete original after encrypting:

del Secret.txt

Decrypt:

7z x -pMySecret123 locked.7z

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How to Use the Script

1. Run the .bat file.
2. Choose an option:
   • 1 → Lock/Encrypt
   • 2 → Unlock/Decrypt
   • 3 → Exit
3. For encryption:
   • Enter full path to file/folder
   • Specify F (file) or D (folder)
   • Enter a password (leave blank for default)
4. For decryption:
   • Enter full path to .7z archive
   • Enter password (or leave blank for default)

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Notes

• You must have 7-Zip installed and added to your PATH.
• The script removes the original after successful encryption/decryption.
• Encrypted archives can be opened with any tool that supports .7z and the password.