File Encryption and Decryption Tool (cryptography)

This Python script allows you to encrypt and decrypt files.

Encryption Types/Methods

• Fernet: Symmetric encryption for secure file storage.
• AES: Advanced Encryption Standard, a widely-used symmetric encryption algorithm.

Features

• Entropy Calculation: Determines if a file is likely encrypted based on its entropy value (Shannon entropy).
• Fernet Encryption: Encrypt files with Fernet symmetric encryption.
• AES Encryption: Encrypt files using AES with CBC mode (supporting key sizes of 16, 24, or 32 bytes).
• Encryption Key Management: Saves the generated encryption keys for later decryption.
• Decryption: Decrypt files using the saved keys (for both Fernet and AES encryption).

Requirements

• Python 3.x
• cryptography library (for encryption)

Installation

1. Clone or download the repository.
2. Install the Python dependencie:

pip install cryptography

Usage

Encrypt a File

1. Run the script.
2. Enter the full path of the file you want to encrypt.
3. Choose whether to encrypt using Fernet or AES.
4. If using AES, select the key size (16, 24, or 32 bytes).

The tool will create a new file prefixed with encrypted- and save the encryption key in a separate file with the prefix key-.

Decrypt a File

1. Run the script.
2. Enter the full path of the encrypted file.
3. Choose whether to decrypt using Fernet or AES.
4. Enter the encryption key when prompted.

The tool will create a new file with the .decrypted suffix.

Example

Enter the full path of the file: /home/user/file.txt
This file is not encrypted.
Do you want to encrypt the file? (yes/no): yes
Choose encryption method (Fernet or AES): Fernet
File encrypted as encrypted-file.txt
Key saved as key-file.txt