Educational Research Tool

MOSS Bypasser

Demonstrates how easily MOSS plagiarism detection can be bypassed with simple code transformations

⚠️ Educational Purpose Only
This tool is for educational and research purposes to demonstrate vulnerabilities in MOSS detection. It shows why modern detection systems like Codequiry are necessary for academic integrity.

Note: Mossad is another tool by UMass that demonstrates how to break MOSS detection, highlighting the need for more robust plagiarism detection systems.
Original Code Source
Transformed Code MOSS Bypassed
Applied Transformations

Understanding MOSS Vulnerabilities

🎯 What is MOSS?

MOSS (Measure of Software Similarity) is a plagiarism detection system developed by Stanford University in 1994. It uses text pattern matching to detect code similarity in programming assignments.

🔓 Known Limitations

MOSS can be bypassed using simple transformations: variable renaming, loop restructuring, comment injection, and whitespace changes. These modifications break pattern matching while preserving functionality.

🛠️ Other Tools

Mossad, developed by researchers at UMass, is another tool that demonstrates how MOSS can be defeated. These tools highlight the need for more advanced detection systems that understand code semantics, not just syntax.

Why Modern Detection Matters

  • Text-based matching only - doesn't understand code logic
  • Cannot detect AI-rewritten code (ChatGPT, Copilot)
  • Vulnerable to simple obfuscation techniques
  • Modern systems use semantic analysis to detect similarity even after transformation

Modern Plagiarism Detection

Unlike MOSS's text-matching approach, modern detection systems like Codequiry use AI to understand code semantics:

  • Semantic analysis - understands code logic, not just text patterns
  • AI-powered detection - adapts to new obfuscation techniques
  • Detects AI-rewritten code from ChatGPT and similar tools
  • Web and repository scanning for online sources
  • Behavioral analysis to identify similar algorithms
Learn More About Codequiry