Create README.md

Author: JawadSher

Project 12 - File Encryptor Decryptor/README.md

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+# File Encryptor and Decryptor
+
+## Overview
+
+The File Encryptor and Decryptor is a Python project that provides a simple yet secure way to encrypt and decrypt files. Using the `cryptography` library, this project allows users to generate a key, encrypt files with this key, and decrypt files using the same key. This ensures that sensitive data is protected from unauthorized access.
+
+## Features
+
+-   **Key Generation**: Generate a secure encryption key and save it to a file.
+-   **File Encryption**: Encrypt any file and save the encrypted data to a new file.
+-   **File Decryption**: Decrypt an encrypted file using the saved key and save the decrypted data to a new file.
+
+## Prerequisites
+
+Before you begin, ensure you have met the following requirements:
+
+-   Python 3.x installed on your computer.
+-   `cryptography` library installed. You can install it using pip:
+
+bash
+
+Copy code
+
+`pip install cryptography` 
+
+## Setup
+
+1.  **Clone the repository:**
+
+```
+git clone https://github.com/JawadSher/Python-Projects-Beginner-to-Advance/tree/main/Project%2012%20-%20File%20Encryptor%20Decryptor
+``` 
+
+2.  **Navigate to the project directory:**
+
+
+`cd File-Encryptor-Decryptor` 
+
+3.  **Run the script:**
+
+
+`python encryptor_decryptor.py` 
+
+## Usage
+
+### Generate a Key
+
+1.  Run the script and choose option `1` to generate a key.
+2.  Enter the desired filename to save the key (e.g., `mykey`).
+3.  The key will be saved in a file named `mykey.key`.
+
+### Encrypt a File
+
+1.  Run the script and choose option `2` to encrypt a file.
+2.  Enter the name of the file you wish to encrypt.
+3.  Enter the name of the file to save the encrypted data (e.g., `encrypted_data`).
+4.  The encrypted data will be saved in a file named `encrypted_data.txt`.
+
+### Decrypt a File
+
+1.  Run the script and choose option `3` to decrypt a file.
+2.  Enter the name of the file you wish to decrypt.
+3.  Enter the name of the file to save the decrypted data (e.g., `decrypted_data`).
+4.  The decrypted data will be saved in a file named `decrypted_data.txt`.
+
+### Exit
+
+-   Choose option `4` to exit the script.
+
+## Code Explanation
+
+### Key Generation
+
+
+```
+def generate_key():
+    key = Fernet.generate_key()
+    k_file = input("Enter file to save key : ")
+    with open(f"{k_file}.key", 'wb') as key_file:
+        key_file.write(key)
+        print(f"Key saved successfully at file: {k_file}.key")
+``` 
+
+-   Generates a key using `Fernet.generate_key()`.
+-   Saves the key to a specified file.
+
+### Load Key
+
+
+```
+def load_key():
+    key_file = input("Enter the key file Name to load key: ")
+    return open(f'{key_file}.key', 'rb').read()
+``` 
+
+-   Loads the key from a specified file.
+
+### Encrypt File
+
+
+```
+def encrypt_file(f_name):
+    key = load_key()
+    fernet = Fernet(key)
+    with open(f'{f_name}', 'rb') as file:
+        f_data = file.read()
+    encrypted_data = fernet.encrypt(f_data)
+    f_name = input("Enter the file to save Encrypted Data : ")
+    with open(f'{f_name}.txt', 'wb') as file:
+        file.write(encrypted_data)
+        print(f"Data Encrypted successfully at file: {f_name}")
+``` 
+
+-   Reads the file to be encrypted.
+-   Encrypts the data using the loaded key.
+-   Saves the encrypted data to a specified file.
+
+### Decrypt File
+
+```
+def decrypt_file(f_name):
+    key = load_key()
+    fernet = Fernet(key)
+    data = open(f"{f_name}", 'rb').read()
+    decrypted_data = fernet.decrypt(data)
+    n_file = input("Enter file name to save Decrypted Data : ")
+    with open(f"{n_file}.txt", 'wb') as file:
+        file.write(decrypted_data)
+        print(f"Plain text data saved at file: {n_file}.txt")
+``` 
+
+-   Reads the encrypted file.
+-   Decrypts the data using the loaded key.
+-   Saves the decrypted data to a specified file.
+
+### Main Menu
+
+```
+def main():
+    print('------> Welcome to File Encryptor and Decryptor <------')
+    print()
+    print("1. Generate Key")
+    print("2. Encrypt File")
+    print("3. Decrypt File")
+    print("4. Exit")
+    print()
+    choice = input("Enter your choice : ")
+    if choice == '1':
+        generate_key()
+    elif choice == '2':
+        file_name = input("Enter the name of the file to encrypt: ")
+        encrypt_file(file_name)
+        print(f"{file_name} has been encrypted.")
+    elif choice == '3':
+        file_name = input("Enter the name of the file to decrypt: ")
+        decrypt_file(file_name)
+        print(f"{file_name} has been decrypted.")
+    elif choice == '4':
+        exit()
+    else:
+        print("Invalid choice. Please try again.")
+
+if __name__ == '__main__':
+    while True:
+        main()
+``` 
+
+-   Provides a menu for the user to choose an action.
+-   Executes the chosen action.
+
+## Execution Examples
+
+### Example 1: Generate a Key
+
+1.  **Run the script** and choose option `1` to generate a key:
+    
+    
+    `python encryptor_decryptor.py` 
+    
+2.  **Select Option 1:**
+    
+    
+    ```
+    ------> Welcome to File Encryptor and Decryptor <------
+    
+    1. Generate Key
+    2. Encrypt File
+    3. Decrypt File
+    4. Exit
+    
+    Enter your choice: 1
+    ``` 
+    
+3.  **Enter the desired filename to save the key:**
+    
+    Copy code
+    
+    `Enter file to save key: mykey
+    Key saved successfully at file: mykey.key` 
+    
+
+### Example 2: Encrypt a File
+
+1.  **Run the script** and choose option `2` to encrypt a file:
+    
+
+    
+    `python encryptor_decryptor.py` 
+    
+2.  **Select Option 2:**
+    
+    
+     ```
+    ------> Welcome to File Encryptor and Decryptor <------
+    
+    1. Generate Key
+    2. Encrypt File
+    3. Decrypt File
+    4. Exit
+    
+    Enter your choice: 2
+    ``` 
+    
+3.  **Enter the name of the file you wish to encrypt:**
+    
+    
+    `Enter the name of the file to encrypt: plaintext.txt` 
+    
+4.  **Enter the name of the file to save the encrypted data:**
+    
+    
+    ```
+    Enter the file to save Encrypted Data: encrypted_data
+    Data Encrypted successfully at file: encrypted_data
+    ``` 
+    
+
+### Example 3: Decrypt a File
+
+1.  **Run the script** and choose option `3` to decrypt a file:
+    
+    
+    `python encryptor_decryptor.py` 
+    
+2.  **Select Option 3:**
+    
+    
+    ```
+    ------> Welcome to File Encryptor and Decryptor <------
+    
+    1. Generate Key
+    2. Encrypt File
+    3. Decrypt File
+    4. Exit
+    
+    Enter your choice: 3
+    ```  
+    
+3.  **Enter the name of the file you wish to decrypt:**
+    
+    `Enter the name of the file to decrypt: encrypted_data.txt` 
+    
+4.  **Enter the name of the file to save the decrypted data:**
+    
+    
+    `Enter file name to save Decrypted Data: decrypted_data
+    Plain text data saved at file: decrypted_data.txt` 
+    
+
+### Example 4: Exit the Script
+
+1.  **Run the script** and choose option `4` to exit:
+    
+    
+    `python encryptor_decryptor.py` 
+    
+2.  **Select Option 4:**
+   
+    
+    ```
+    ------> Welcome to File Encryptor and Decryptor <------
+    
+    1. Generate Key
+    2. Encrypt File
+    3. Decrypt File
+    4. Exit
+    
+    Enter your choice: 4
+    ``` 
+    
+3.  **Exit the script:**
+   
+    
+    `Goodbye!`