Introduction

The File Encryption Tool is a Python-based application designed to encrypt, decrypt, hide, and unhide files and folders (including nested ones) using AES-128 encryption with CBC mode and PKCS7 padding. It employs PBKDF2 for secure key derivation from a user-provided password. The tool features a graphical user interface (GUI) built with Tkinter, allowing users to select paths, enter passwords, and monitor progress during operations. It supports recursive processing of directories and provides real-time feedback via a progress bar, percentage completion, elapsed time, and estimated remaining time.

This tool is intended for personal use to protect sensitive files. Important: Encryption is only as secure as your password. Use a strong, unique password and keep it secret. Always back up your data before encrypting, as incorrect passwords or corrupted files may result in permanent data loss.

System Requirements

• Operating System: Windows, macOS, or Linux (tested on Python-compatible environments).
• Python Version: Python 3.8 or higher (the script uses features from Python 3.6+).
• Dependencies:
  • cryptography: For encryption/decryption (install via pip install cryptography).
  • Tkinter: Usually included with Python installations; if not, install it via your package manager (e.g., apt install python3-tk on Ubuntu).
• No internet access is required for the tool to function.

Installation

1. Install Python: Download and install Python from the official website (python.org) if not already installed.
2. Install Dependencies:
   • Open a terminal or command prompt.
   • Run: pip install cryptography
3. Download the Script:
   • Save the provided Python script to a file, e.g., file_encryption_tool.py.
4. Run the Script:
   • Navigate to the directory containing the script.
   • Execute: python file_encryption_tool.py (or python3 file_encryption_tool.py on some systems).

The application window should appear upon running.

Running the Application

• Launch the script as described above.
• The GUI will open with fields for password entry, path selection, and operation buttons.
• Logs are written to file_encryption.log in the script's directory for debugging and tracking operations.

Using the GUI

The interface is straightforward and includes the following elements:

1. Password Field

• Label: "Password:"
• This is a secure entry field (shows asterisks as you type).
• Enter a strong password here. It will be used to derive the encryption key via PBKDF2.
• Note: The same password must be used for decryption. Forgetting it will make files unrecoverable.

2. Path Selection

• Label: "Select Folder/File:"
• Enter or paste the full path to a file or folder.
• Use the "Browse" button to select a file or directory via a file dialog.

3. Operation Buttons

• Encrypt & Hide: Encrypts files (and subfiles recursively if a folder) using AES-128, then hides them.
• Decrypt & Unhide: Decrypts files using the provided password, then unhides them.
• Buttons are disabled during operations to prevent concurrent actions.

4. Progress Indicators

• Progress Bar: Shows overall completion as a horizontal bar (0-100%).
• Percentage: Displays current progress (e.g., "45.67%").
• Elapsed Time: Shows time spent so far (e.g., "Elapsed: 12.34s").
• Remaining Time: Estimates time left based on current speed (e.g., "Remaining: 15.67s").
• These update in real-time during encryption/decryption.

Step-by-Step Usage

1. Enter Password: Type your password in the field.
2. Select Path: Use the entry field or "Browse" to choose a file or folder.
3. Choose Operation:
   • For encryption: Click "Encrypt & Hide".
   • For decryption: Click "Decrypt & Unhide".
4. Monitor Progress: Watch the indicators as the tool processes files chunk-by-chunk (to handle large files efficiently).
5. Completion: A message box will appear upon success (e.g., "Encrypted and processed 5 files.") or error (e.g., with details like "Invalid password").
6. Close the App: Use the window close button when done.

Handling Folders

• The tool recursively processes all files in the selected folder and its subfolders.
• Subdirectories (except the root) are also hidden/unhidden.
• On Unix-like systems (macOS/Linux), hiding prefixes names with a dot (e.g., ".hiddenfolder").
• On Windows, it sets the hidden file attribute.
• Note: Hidden files/folders may not appear in file explorers by default; enable "Show hidden files" in your OS settings to view them.

Features

• Encryption Algorithm: AES-128 in CBC mode with random IV and salt per file for security.
• Key Derivation: PBKDF2 with SHA-256 and 480,000 iterations for resistance against brute-force attacks.
• Chunked Processing: Handles large files without loading everything into memory.
• Hiding Mechanism: OS-specific for maximum compatibility.
• Logging: Detailed logs in file_encryption.log including timestamps, errors, and successes.
• Threaded Operations: Background processing keeps the GUI responsive.
• Error Handling: Try-except blocks catch issues like invalid paths or decryption failures, showing user-friendly messages.

Troubleshooting

• Error: "Password is required.": Ensure you entered a password.
• Error: "Path is required.": Select a valid file or folder.
• Decryption Fails: Likely due to wrong password or non-encrypted file. Check logs for details.
• Hidden Files Not Visible: Enable hidden file viewing in your file manager (e.g., Ctrl+H on Linux, View > Hidden items on Windows).
• Performance Issues: For very large folders, operations may take time; the remaining time estimate helps.
• Library Not Found: If cryptography is missing, reinstall via pip.
• Cross-OS Compatibility: Encrypted files can be decrypted on any OS, but hiding may need manual adjustment if moving between Windows and Unix.

Security Notes

• Password Strength: Use at least 12 characters with mixes of letters, numbers, and symbols.
• Backup: Always back up originals before encrypting.
• Limitations: This is not GPG-based as initially requested (the script uses cryptography library instead for simplicity). For GPG, consider tools like gpg command-line.
• Legal: Ensure compliance with local laws on encryption.
• No Warranty: This tool is provided as-is; test on non-critical data first.