Multiple Cryptographic Functionalities

Overview

This Python application integrates various cryptographic functionalities into a single interactive program. Users can perform encryption, decryption, hashing, digital signature generation/verification, and Message Authentication Code (MAC) generation.

Developed by Alina Hasan

---

Features

1. AES Encryption/Decryption
   Supports encryption and decryption using AES in ECB or CBC modes. Users can input plaintext/ciphertext, specify the AES mode, provide keys, and select the desired operation.

2. RSA Encryption/Decryption
   Implements RSA for encrypting and decrypting messages. Users can generate RSA keys and perform encryption or decryption.

3. Hashing
   Provides hashing functionalities using SHA1, SHA256, and MD5. Users can input data and select the hashing algorithm.

4. Digital Signature using RSA
   Facilitates the creation and verification of digital signatures to ensure message integrity and authenticity.

5. MAC Generation
   Supports generation of Message Authentication Codes using CMAC (Cipher Block Chaining-MAC) and HMAC (Hash-based Message Authentication Code).

---

Installation

Before running the program, install the required cryptographic library:

pip install pycryptodome

---

Usage

Running the Application

Run the program in a Python environment. Upon execution, a menu will appear with the following options:

1. AES Encryption/Decryption

   • Choose ECB or CBC mode.
   • Specify whether to encrypt or decrypt.
   • Input the message and key.

2. RSA Encryption/Decryption

   • Generate RSA keys (private and public).
   • Choose encryption or decryption.
   • Input the required keys and message.

3. Hashing

   • Select the hashing algorithm (SHA1, SHA256, or MD5).
   • Input the message to hash.

4. Digital Signature using RSA

   • Generate a signature or verify an existing one.
   • Provide the necessary keys and message.

5. MAC Generation

   • Choose between CMAC and HMAC.
   • Input the message to generate the MAC.

6. Exit

   • Quit the application.

---

Examples

AES Encryption

• Mode: CBC
• Message: HelloWorld
• Key: mysecretkey

Encrypted text: b'\xab\xcd\xef...'
Decrypted text: HelloWorld

RSA Encryption

• Generate keys:

  • Prime Numbers: p = 17, q = 23
  • Public Key (e, N): (3, 391)
  • Private Key (d): 275

• Encrypt: M = 42

  Encrypted message: 180
  

• Decrypt: C = 180

  Decrypted message: 42
  

Hashing

• Algorithm: SHA256
• Message: SecureHash

Hash Value: 7c2a55...e3a6f9

Digital Signature

• Message: VerifyThis
• Signature: Generated using RSA private key.
• Verification: Valid or Invalid.

MAC Generation

• Message: AuthenticateMe
• CMAC/HMAC: Generates a unique signature for the message.

---

Implementation Details

Modules Used

• pycryptodome for cryptographic functionalities.
• hashlib, base64, os, hmac for supporting utilities.

Cryptographic Algorithms

• AES: Encryption/Decryption using block ciphers.
• RSA: Public/Private key cryptography for secure communication.
• SHA1/SHA256/MD5: Hash functions for integrity.
• MAC: Ensures authenticity using CMAC or HMAC.

Input Validation

• Prime checking using is_prime function.
• Coprime validation for RSA key generation.

---

Future Improvements

• Extend support for additional algorithms (e.g., DES, RSA-OAEP).
• Add a GUI for improved user experience.
• Provide more robust error handling for invalid inputs.

---

License

This project is for academic purposes. Redistribution or commercial use is prohibited without permission.

---

Contact

Alina Hasan
Email: alina.hasan@g.bracu.ac.bd
ID: 20101301