The uncomfortable truth about modern software development: Every time your developers use LLMs/GPTs to write code, they might be introducing problematic code into your proprietary codebase. And you won’t know until it’s too late.
The Problem: AI Doesn’t Respect License Boundaries
Consider this scenario:
Your engineering team is building a commercial video streaming platform. A developer asks an AI assistant: “Write a plugin for the app that implements an efficient video compression for low latency networks.”
The AI obliges. The code works beautifully. Six months later, you discover the AI reproduced H.264 CABAC encoding, a patented algorithm with significant licensing fees and GPL-licensed implementations from FFmpeg source code.
Your options now?
- Pay retroactive licensing fees and ongoing royalties
- Face patent infringement litigation
- Open-source your entire product under GPL (destroying your business model)
- Go rogue and face risks together with potential negative noise for your company.
- Spend weeks doing a complete rewrite under time pressure
This isn’t hypothetical. AI coding assistants are trained on billions of lines of public code, including GPL-licensed code, Audio/Video patented codec implementations, and restrictive-license libraries. When they generate code, they’re effectively doing a probabilistic remix of their training data with licenses and all.
Why Traditional Tools Don’t Work
You might think: “We already scan for license violations using Dark Crow or Sniff (fake names of real apps).”
Here’s the problem: AI doesn’t copy-paste code. It transforms it:
- Translates languages: Takes C code from ffmpeg, outputs Java or Python
- Renames everything:
rb_rotate_left()becomesrotate_node_left() - Modernizes style:
for(int i=0; i<n; i++)becomesfor i in range(n) - Refactors structure: Single function split across multiple classes
Traditional software composition analysis (SCA) tools rely on imports, strings, exact matching or simple fuzzy hashing. They’re designed to catch copy-paste plagiarism, not AI-mediated code transformation.
The result? Tools like Dark Crow detect only 67% of GPL content in AI-generated code. Sniff manages 70%. That means 30%+ of your legal exposure stays hidden, and the more serious risks are in that magical 30%.
Introducing CopycatM: DNA Testing for Code
What if you could create a “fingerprint” of source code that persists even when an AI completely rewrites it?
CopycatM solves this problem using transformation-resistant signatures—multi-layered fingerprints that survive variable renaming, language translation, and structural refactoring.
Think of it like DNA testing: your DNA stays the same whether you dye your hair, change your clothes, perform a full plastic surgery, or speak a different language. Similarly, CopycatM identifies code by its underlying algorithmic structure, not just its superficial appearance.
How CopycatM Creates Transformation-Resistant Signatures
CopycatM uses a three-tier architecture where each layer provides a different type of protection:
Tier 1: Forensic Baseline — The Foundation
What it does: Creates multiple cryptographic and fuzzy fingerprints of your code. It could sound similar to other implementations, but it’s not.
This tier catches exact copies and minor modifications (76% detection rate on transformed code)
Think of Tier 1 as your first line of defense. It generates several complementary fingerprints simultaneously:
- Exact fingerprints: Perfect for detecting copy-paste with zero changes
- Fuzzy fingerprints: Survive ~10% character changes, comment additions, minor refactoring
- Semantic fingerprints: Detect partial code reuse and variable renaming, it doesn’t implement the fingerprinting mechanism over the code, instead applies over the semantic in the code.
Even when the developer renames all variables in a binary search algorithm (arr → data, target → value, low → start), the tool will detect 70% of similarity (structurals patterns preserved). This helps detect variations on simple (low cyclomatic complexity) implementations capturing 70% of similarity cases.
Tier 2: Pattern Recognition — The Detective
It focuses on catching “Substantial Similarity” between implementations. Scans for known algorithm patterns using semantic analysis, identifying 65-70 known patented and GPL algorithms with 95% accuracy.
Tier 2 looks beyond syntax to recognize what the code actually does, for example:
- Detects H.264 CABAC encoding even when renamed and refactored
- Identifies AES encryption regardless of variable names
- Recognizes GPL-licensed red-black tree rotations across languages
The clever part: Tier 2 doesn’t just detect similarities—it labels what it finds using CopycatM Reference DB:
- “This matches Linux kernel rb-tree implementation (GPL-2.0)”
- “This is H.264 CABAC entropy encoding (patented)”
- “This resembles MongoDB aggregation pipeline (AGPL)”
What happens if Tier 2 doesn’t recognize your proprietary algorithm? Don’t worry—Tiers 1 and 3 still work perfectly. Your code gets fully fingerprinted regardless.
Tier 3: Semantic Deep Analysis — The Game Changer
This tier uses neural network analysis to create structure-based fingerprints that work across programming languages, achieving 79% detection rate on cross-language translations (C → Python, JavaScript → Go, etc.)
This is where CopycatM pulls ahead of traditional tools. Tier 3 analyzes the logical flow of your code, not the text. It transforms any source code implementation into a standardized representation across languages, extracting mathematical invariants—deep structural properties that survive transformations, to create an structural fingerprint using advanced pattern recognition.
This specific invariants capture the essential “shape” of an algorithm in a way that’s resistant to cosmetic changes. So, when AI translates GPL code from C to Python, traditional tools see two completely different files. Tier 3 sees the same DNA, the same algorithm.
The Dynamic Transformation Score: Multi-Layer Defense
Here’s where CopycatM’s architecture really shines: redundancy by design.
When analyzing code, CopycatM doesn’t rely on a single detection method. Instead, it combines evidence from all three tiers using a weighted similarity score:
Final Similarity =
40% × Fuzzy hashing (Tier 1)
30% × Pattern and semantic match (Tier 1)
20% × Exact hash match (Tier 1)
10% × Neural network structure (Tier 3)
+ calibration scoring if Tier 2 identifies matching algorithm type
Even if an AI transformation defeats one or two detection methods, the others still catch it. The good news? AI models use systematic renaming patterns and preserve algorithmic structure. This makes them more detectable than random human rewrites.
Beyond Contamination Detection: Track Your Proprietary Algorithms
While we’ve focused on detecting contamination, CopycatM’s architecture works for any code you want to track:
Use cases:
- Code leak detection: Fingerprint your proprietary algorithms, detect if they appear in competitor products
- Forensic provenance: Create tamper-evident signatures for code authorship tracking
- License compliance: Scan third-party dependencies for restrictive licenses
- Security audits: Detect known vulnerable code patterns
The flexibility: CopycatM’s three-tier approach works on both known and unknown algorithms. You can:
- Use built-in patterns for 65-70 common GPL/patented algorithms
- Define custom patterns for your proprietary code
- Rely on Tier 1 + Tier 3 when no patterns exist
The Future of Code Compliance is Here
AI coding assistants aren’t going away, instead they will only get better at writing code—and better at disguising where that code came from.
You have two choices:
- Ban AI assistants (lose productivity, fall behind competitors)
- Detect contamination proactively (keep velocity, manage risk)
CopycatM makes option 2 viable.
Getting Started
CopycatM is currently in private beta. We’re planning AGPL-3.0 release in Q2 2026.
What you can do now:
- Request early access for evaluation
- Review our technical documentation and validation methodology
- Run a pilot scan on a subset of your codebase
The Bottom Line
CopycatM doesn’t just scan code, it creates transformation-resistant DNA fingerprints that survive everything AI throws at them.
Your proprietary code deserves protection. Your legal team deserves peace of mind. Your developers deserve tools that work.
Because in the age of AI-generated code, what you can’t detect will hurt you.
For technical details, see our research paper: “CopycatM: Detecting Third-Party License and Patent Contamination in AI-Generated Code”
For early access inquiries: [contact information]
Appendix: Technical FAQ
Q: Can AI detect that you’re using CopycatM and evade it? A: The three-tier redundancy makes evasion extremely difficult. To evade detection, AI would need to change the algorithm’s fundamental logic—at which point it’s no longer the same algorithm.
Q: What about code that’s legitimately similar (e.g., everyone implements binary search the same way)? A: CopycatM uses algorithm-specific thresholds. Common patterns like binary search require 70% match (not 50%) and must match multiple evidence types to trigger alerts.
Q: Does CopycatM work on obfuscated code? A: Tier 3’s structural analysis handles some obfuscation, but intentionally mangled logic (fake loops, dead code) can reduce detection rates. However, most AI-generated code isn’t obfuscated—AI optimizes for readability.
Q: How does CopycatM handle partial code reuse (e.g., only 30% of a file is copied)? A: MinHash (Tier 1) specifically detects partial reuse with 91% accuracy on code snippets as small as 50 lines. The system analyzes both file-level and block-level similarities.
Q: What’s the performance impact on CI/CD pipelines? A: Signature extraction: ~200ms per file. Matching: <1 second. For a typical commit (10-50 files), total overhead is 2-10 seconds. Most teams run full scans nightly and incremental scans on PRs.
Q: Can I use CopycatM to detect proprietary algorithm leaks? A: Yes. Extract signatures from your proprietary codebase, then compare against suspected leaks, competitor products, or public repositories. The same fingerprinting technology works for any code tracking use case.
Q: Can CopycatM detect problematic security implementations, like log4j vulnerabilities or weak cryptographic algorithms? A: Absolutely. CopycatM’s pattern recognition (Tier 2) can identify known vulnerable code patterns beyond just license violations. You can build reference libraries from:
- Known vulnerable implementations (log4j RCE patterns, Heartbleed, etc.)
- Deprecated cryptographic algorithms (MD5, SHA-1, DES)
- Insecure coding patterns (SQL injection vulnerable code, buffer overflows)
- Banned algorithm implementations in regulated industries
The three-tier architecture detects these patterns even when AI rewrites them with different variable names or translates them to another language. This makes CopycatM valuable for security audits, not just license compliance.