🎯 Password Strength Checker with Common Password Detection

Author: D0up4
Last Updated: 06/2025
Project Type: Cybersecurity / Password Security Tool

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📘 Description

This is a Python-based password strength checker designed to help users and security professionals evaluate password robustness. It combines traditional strength checks based on company password policies with a check against the well-known rockyou.txt list of common passwords.

The tool:

• ✅ Flags passwords found in the rockyou.txt common password list as very weak.
• ✅ Enforces company-style password requirements:
  • Minimum length (default 12 characters)
  • At least one uppercase letter
  • At least one lowercase letter
  • At least one digit
  • At least one special character
• ✅ Calculates password entropy to estimate randomness and strength.
• ✅ Provides clear, actionable feedback for improving passwords.

This is ideal for personal use, cybersecurity training, or as part of a portfolio demonstrating password security awareness.

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⚙️ Features

• Common Password Detection: Uses the rockyou.txt password list to identify weak, frequently used passwords.
• Company Password Policy Checks: Verifies password meets common corporate security standards.
• Entropy Calculation: Estimates password randomness in bits.
• Detailed Feedback: Offers step-by-step guidance on strengthening passwords.
• Lightweight: Pure Python, no heavy dependencies.

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🚀 Usage

1. Ensure you have the rockyou.txt file in the same directory as the script (or update the path in the code).
   The rockyou.txt password list can be downloaded from various public repositories (e.g., SecLists on GitHub).

2. 🧪 Run the script:

   python password_strength_checker.py