In today's digital world, passwords remain the first line of defence for protecting sensitive information. Yet, weak passwords remain one of the primarycauses of security breaches. As part of my cybersecurity internship, I decided to explore this problem by building a Password Complexity Checker using Python.

This project was not just about writing code — it was about understanding how security principles translate into real-world applications, and how simple tools can significantly improve digital safety.

Why Build a Password Complexity Checker?

Despite advancements in cybersecurity, weak passwords are still one of the most common vulnerabilities. Many users choose passwords that are:

  • Short
  • Predictable
  • Numeric-only
  • Easy to guess

Attackers exploit this behaviour using techniques such as brute force attacks, dictionary attacks, and credential stuffing. This makes password strength validation a critical security measure.

I wanted to create a tool that could:

  • Educate users about password security.
  • Provide clear feedback on password strength.
  • Encourage better password creation habits.

This led to the development of a Password Complexity Checker — a simple but powerful Python-based security tool.

Project Objective

The goal of this project was to design a system that:

  • Evaluates password strength using multiple security parameters
  • Generates a detailed strength report
  • Provides clear suggestions for improvement
  • Helps users understand why their password is weak or strong

Rather than simply labelling a password as weak or strong, the tool explains how the result was determined.

Core Evaluation Criteria

The checker evaluates each password based on the following security rules:

  • Minimum length of 8 characters
  • Presence of uppercase letters
  • Presence of lowercase letters
  • Inclusion of numeric characters
  • Use of special characters
  • Absence of whitespace

Each parameter contributes to the final strength score, ensuring a fair and realistic evaluation.

How the System Works

  1. User Input The user enters a password through the terminal.
  2. Validation Process The program checks the password against each complexity rule.
  3. Scoring Mechanism Each satisfied criterion increases the strength score, producing:
  • Total score out of 8
  • Percentage score
  1. Strength Classification Based on the score, the password is classified as:
  • Weak
  • Strong
  1. Detailed Report Generation The system outputs:
  • Password length
  • Strength score
  • Percentage rating
  • Strength label
  • Pass/fail checklist for each rule.
  • Suggestions to improve weak passwords

Sample Output Insights

  • A password containing uppercase, lowercase, numbers, and special characters, with sufficient length, typically scores 8/8 (Strong).
  • A numeric-only password such as 123456789 scores 4/8 (Weak) and receives suggestions to add letters and special symbols.

This feedback-based design helps users immediately understand what changes are needed to improve security.

Technical Implementation

The project was developed using Python, with a focus on clarity, readability, and efficiency.

Key technical concepts used include:

  • Input validation
  • Conditional logic
  • String handling and pattern detection
  • Logical flow control
  • Structured output formatting

The design emphasises clean coding practices while maintaining high usability.

What I Learned

This project helped me gain practical experience in:

  • Secure input validation
  • Designing rule-based evaluation systems
  • Writing structured terminal reports
  • Understanding real-world authentication security
  • Applying cybersecurity fundamentals through coding

Beyond technical skills, it strengthened my awareness of human behaviour in cybersecurity and how usability and education are just as important as encryption and firewalls.

Why This Project Matters

Many security breaches begin with weak authentication practices. While advanced security solutions exist, strong passwords remain one of the simplest and most effective defence mechanisms.

Tools like this:

  • Encourage better password habits.
  • Improve user awareness
  • Reduce vulnerability to basic attacks.
  • Support a security-first mindset.

Final Thoughts

Building the Password Complexity Checker was a rewarding experience that bridged the gap between programming and cybersecurity principles. It demonstrated how simple logic, when applied thoughtfully, can significantly improve security.

This project reinforced an important lesson:

Strong security starts with small, consistent, and intelligent decisions.

GitHub Repository

🔗 https://github.com/manividyadhar/internship_1-password_checker