An educational Python implementation of Caesar Cipher brute-force cryptanalysis. This project demonstrates how classical encryption can be broken using exhaustive search and simple English frequency scoring.
It is designed as a learning and academic project to understand why classical ciphers are insecure and how attackers analyze encrypted text — not as a real-world attack tool.
caesar-cipher-cryptanalysis-python/
│
├── assets/ # Screenshots
├── app.py # Brute-force Basic CLI Version
├── interactive.py # Rich-powered CLI
├── requirements.txt # Dependencies
├── LICENSE # Project license
└── README.md # Project documentation- Tests all 25 possible Caesar shifts
- Supports both:
L→ Left shiftR→ Right shift
- Automatically evaluates all possible plaintext candidates
- Uses frequency-based heuristic scoring
- Prioritizes common English letters (E, T, A, O, I, N, etc.)
- Rewards spaces and readable structure
- Ranks outputs automatically
- Sorts plaintext candidates by likelihood
- Displays top possible decryptions
- Removes mirror duplicate results
- Demonstrates cryptanalysis workflow
- Shows weakness of classical substitution ciphers
- Reinforces modular arithmetic concepts
- Clean and modular Python implementation
- Beautiful colored terminal UI using Rich
- Displays key matrix in a structured table 🔥
- Interactive prompts with validation
- Clean and readable output panels
- 🧼 Basic CLI → Lightweight, no dependencies
- 🎨 Rich CLI → Enhanced UI with colors and structured display
| Technology | Role |
|---|---|
| Python 3 | Core programming language |
| ord() / chr() | Character-to-ASCII conversion |
| Modular Arithmetic | Circular alphabet shifting (% 26) |
| Heuristic Scoring | English-likeness evaluation |
| Rich | Styled CLI, colors, panels |
This project is built to:
- Understand Caesar Cipher weaknesses
- Learn brute-force cryptanalysis
- Explore basic frequency analysis concepts
- Simulate attacker perspective ethically
- Strengthen Python logic and modular design skills
⚠️ This project is intended strictly for educational and cybersecurity learning purposes.
git clone https://github.com/ShakalBhau0001/caesar-cipher-cryptanalysis-python.gitcd caesar-cipher-cryptanalysis-pythonpip install richOR
pip install -r requirements.txtpython app.pypython interactive.py- Provide any Caesar-encrypted message
- View automatically ranked possible plaintexts
- Analyze shift and direction results
Enter Caesar cipher text: QEB NRFZH YOLTK CLU GRJMP LSBO QEB IXWV ALD
Top Possible Plaintexts:
Shift 3 | Dir R | Score 72 | THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
Shift 23 | Dir L | Score 72 | THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
...- English scoring is heuristic-based (not statistical-grade)
- Works only for Caesar Cipher
- Not designed for real-world encrypted systems
- CLI-based interaction only
- Implement full frequency distribution comparison
- Add dictionary-based validation
- Support file input
- Add support for other classical ciphers
- Convert into reusable Python module
- Add Rich tables for result visualization
This project is created for educational and cybersecurity learning purposes only. It demonstrates the inherent weakness of classical substitution ciphers such as Caesar Cipher. It must not be used for unauthorized access, malicious activity, or real-world security attacks.
Shakal Bhau
GitHub: ShakalBhau0001
If you like this project, consider giving it a ⭐ on GitHub!