🛡️ PassShield

PassShield is a full-stack web application that analyzes password strength using entropy-based metrics, character set analysis, and real-world cracking simulations. It provides users with detailed insights into password security through an intuitive, modern interface.

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🚀 Key Features

• Password Strength Scoring: Rates passwords on a scale of 0–100 based on multiple factors.
• Entropy Calculation: Estimates password complexity in bits.
• Character Set Detection: Identifies use of lowercase, uppercase, digits, and special characters.
• Common Password Detection: Flags passwords appearing in known leak databases or wordlists.
• Time-to-Crack Estimation: Simulates attack scenarios (brute-force, dictionary, hybrid).
• Modern UI: Built with React for real-time feedback and smooth user experience.

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🧩 Project Structure

PassShield/
├── backend/ # Flask API
│ ├── app.py # Main server (exposes /analyze_password)
│ ├── password_cracker.py # Entropy, charset, and time-to-crack logic
│ └── requirements.txt
└── frontend/ # React App (UI)
├── src/components/PasswordAnalyzer.js
└── package.json

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🧠 Tech Stack

• Frontend: React (Create React App)
• Backend: Python 3.9+ with Flask
• Communication: REST API (Frontend → Backend)
• Local Development Ports:
  • Frontend → http://localhost:3000
  • Backend → http://localhost:8000

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⚙️ Run Locally (macOS / Linux / Windows)

🖥️ Backend Setup

# Create and activate a virtual environment
python3 -m venv .venv
source .venv/bin/activate           # macOS / Linux
.venv\Scripts\activate              # Windows

# Navigate to backend and install dependencies
cd backend
pip install -r requirements.txt

# Run Flask server
python3 app.py

By default, the backend runs on port 8000. If there’s a conflict, change the port in app.py or stop the conflicting process.

💻 Frontend Setup

# Navigate to frontend folder
cd ../frontend

# Install dependencies
npm install

# Start the React development server
npm start

Then open http://localhost:3000 in your browser.