Cryptography Toolbox

A comprehensive Python-based cryptography toolkit implementing various classical and modern encryption algorithms, cryptanalysis techniques, and key exchange protocols.

Author:Abood Al Hajjaj - @alhajjajabood,Mohammad Nakhleh - @Moevo

Date: December 2025

📋 Overview

This project is a complete cryptography suite that allows users to:

• Encrypt and decrypt messages using various ciphers
• Perform cryptanalysis through brute force and frequency analysis
• Generate cryptographic keys for asymmetric algorithms
• Simulate attacks like MITM (Man-in-the-Middle) on key exchange protocols

🔐 Supported Algorithms

Symmetric Key Cryptography

• Caesar Cipher - Simple substitution cipher
• Multiplicative Cipher - Affine cipher without addition
• Affine Cipher - Combination of multiplicative and Caesar ciphers
• Playfair Cipher - Digraph substitution cipher
• Hill Cipher - Polygraphic substitution using linear algebra
• DES (Data Encryption Standard) - Block cipher with Feistel structure
• AES (Advanced Encryption Standard) - Modern block cipher

Asymmetric Key Cryptography

• RSA - Public-key cryptosystem
• Diffie-Hellman Key Exchange (DHKE) - Secure key exchange protocol
• ElGamal Encryption - Public-key cryptosystem based on discrete logarithms

Cryptanalysis Tools

• Brute Force Attacks - Exhaustive key search
• Frequency Analysis - Statistical analysis of ciphertext
• Known Attacks - BSGS (Baby-Step Giant-Step), Pollard's p-1, etc.

🚀 Features

1. Interactive Menu System - Easy navigation through different algorithms
2. Educational Focus - Shows step-by-step encryption/decryption processes
3. Attack Simulations - Demonstrates real cryptographic attacks
4. File Output - Saves analysis results to text files
5. Error Handling - Validates inputs and prevents common mistakes

📁 Project Structure

The main file cryptography.py contains:

• Algorithm implementations (37 different tasks/functions)
• Menu system for user interaction
• Helper functions for common operations

🛠️ Installation & Usage

Prerequisites

• Python 3.x
• No external dependencies required (uses only built-in Python libraries)

Running the Tool

python cryptography.py

Navigation

1. Run the script to see the main menu
2. Select a cipher category (1-10)
3. Choose specific operation within that category
4. Follow prompts to input text, keys, and parameters
5. View results and choose next action

📊 Menu Categories

1. Caesar Cipher - Basic shift cipher operations
2. Multiplicative Cipher - Multiplication-based encryption
3. Affine Cipher - Combined multiplication and addition
4. Playfair Cipher - Matrix-based digraph cipher
5. Hill Cipher - Linear algebra-based encryption
6. DES - Classic 64-bit block cipher
7. AES - Modern 128-bit block cipher
8. RSA - Public-key encryption and attacks
9. DHKE - Key exchange protocol
10. ElGamal - Discrete logarithm-based encryption

⚠️ Important Notes

Security Disclaimer

⚠️ This tool is for EDUCATIONAL PURPOSES ONLY

• These implementations are simplified for learning
• DO NOT USE for securing real-world sensitive data
• Real cryptographic applications require professionally vetted libraries

Key Limitations

• DES uses 64-bit keys (obsolete for real security)
• AES implementation is simplified for education
• RSA uses small keys suitable for demonstration only

📝 Usage Examples

Encrypting with Caesar Cipher

1. Select "Caesar Cipher" from main menu
2. Choose "Encryption"
3. Enter plaintext: "HELLO"
4. Enter key: 3
5. Output: "KHOOR"

Breaking Caesar Cipher with Frequency Analysis

1. Select "Caesar Cipher"
2. Choose "Frequency Attack"
3. Enter ciphertext
4. View all possible decryptions ranked by likelihood

RSA Key Generation

1. Select "RSA"
2. Choose "Key Generation"
3. Enter prime numbers p and q
4. Get public key (e, n) and private key (d, n)

🧪 Educational Value

This project is ideal for:

• Computer science students learning cryptography
• Understanding how different encryption algorithms work
• Visualizing cryptographic attacks in action
• Comparing classical vs. modern encryption techniques

🔍 Sample Output Files

The tool generates several analysis files:

• all_candidates.txt - Hill cipher brute force results
• playfaier_brutN!_attack.txt - Playfair exhaustive key search
• hill_cipher_attack_results_*.txt - Frequency analysis results
• playfair_results_*.txt - Playfair cryptanalysis

🤝 Contributing

This is primarily an educational project, but suggestions for:

• Code improvements
• Additional algorithms
• Better documentation
• Bug fixes

are always welcome.

📚 Learning Resources

To better understand these algorithms:

• "Cryptography and Network Security" by William Stallings
• "The Code Book" by Simon Singh
• Coursera/edX cryptography courses
• Cryptopals challenges

📄 License

🆓 Free to Use and Modify

This project is completely free to:

• Use for educational and personal purposes
• Modify and customize for your needs
• Upgrade with new features and algorithms
• Share with others for learning

You are encouraged to:

• Add new cryptographic algorithms
• Improve existing implementations
• Create better user interfaces
• Fix bugs and optimize performance
• Translate to other programming languages
• Use as a teaching tool in classrooms

No permission required - feel free to fork, modify, and enhance this project!

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Remember: Real-world cryptography requires expert implementation, proper key management, and continuous security assessment. This tool demonstrates concepts but doesn't replace professional cryptographic libraries.

Happy learning! 🔐