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  # ๐Ÿ” AI Text Authentication Platform
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- ## Enterprise-Grade AI Content Authentication
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  ![Python](https://img.shields.io/badge/python-3.8+-blue.svg)
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  ![FastAPI](https://img.shields.io/badge/FastAPI-0.104+-green.svg)
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- ![Accuracy](https://img.shields.io/badge/accuracy-~90%2525+-success.svg)
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  ![License](https://img.shields.io/badge/license-MIT-blue.svg)
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- ![Code Style](https://img.shields.io/badge/code%2520style-black-black.svg)
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  ---
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  ## ๐Ÿ“‹ Table of Contents
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  - [Overview](#-overview)
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  - [Key Differentiators](#-key-differentiators)
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  - [System Architecture](#-system-architecture)
 
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  - [Detection Metrics & Mathematical Foundation](#-detection-metrics--mathematical-foundation)
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  - [Ensemble Methodology](#-ensemble-methodology)
 
 
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  - [Project Structure](#-project-structure)
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  - [API Endpoints](#-api-endpoints)
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- - [Domain-Aware Detection](#-domain-aware-detection)
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- - [Performance Characteristics](#-performance-characteristics)
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  - [Installation & Setup](#-installation--setup)
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- - [Security & Privacy](#-security--privacy)
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- - [Accuracy & Validation](#-accuracy--validation)
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  - [Frontend Features](#-frontend-features)
 
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  - [Business Model & Market Analysis](#-business-model--market-analysis)
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- - [Future Enhancements](#-future-enhancements)
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- - [Support & Documentation](#-support--documentation)
 
 
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  ---
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- ## ๐Ÿš€ Overview
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-
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- The **AI Text Authentication Platform** is a system designed to identify AI-generated content across multiple domains with exceptional accuracy. The platform addresses the growing challenge of content authenticity in education, publishing, hiring, and research sectors.
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-
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- ### What Makes This Platform Unique?
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-
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- The system employs a **sophisticated ensemble of 6 complementary detection metrics** with **domain-aware calibration**, achieving **~90% accuracy** while maintaining computational efficiency, real-time performance, and complete explainability. Unlike traditional single-metric detectors, our platform analyzes text through multiple independent lenses to capture orthogonal signals that AI-generated content exhibits.
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-
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- ### Core Capabilities
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- **Multi-Domain Analysis**
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- - **Academic Domain**: Optimized for essays, research papers, and scholarly writing with specialized linguistic pattern recognition
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- - **Technical Documentation**: Calibrated for medical papers, technical manuals, and documentation with high-precision thresholds
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- - **Creative Writing**: Tuned for stories, narratives, and creative content with burstiness detection
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- - **Social Media**: Adapted for informal writing, blogs, and conversational text with relaxed linguistic requirements
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- **Comprehensive Detection Pipeline**
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- 1. **Automatic Domain Classification**: Intelligent identification of content type to apply appropriate detection parameters
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- 2. **Multi-Metric Analysis**: Parallel execution of 6 independent metrics capturing different aspects of text generation
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- 3. **Ensemble Aggregation**: Confidence-calibrated weighted voting with uncertainty quantification
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- 4. **Model Attribution**: Identifies specific AI models (GPT-4, Claude, Gemini, LLaMA, etc.) with confidence scores
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- 5. **Explainable Results**: Sentence-level highlighting with detailed reasoning and evidence presentation
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- **Market-Ready Features**
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- - **High Performance**: Analyzes 100-500 word texts in 1.2 seconds with parallel computation
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- - **Scalable Architecture**: Auto-scaling infrastructure supporting batch processing and high-volume requests
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- - **Multi-Format Support**: Handles PDF, DOCX, TXT, DOC, and MD files with automatic text extraction
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- - **RESTful API**: Comprehensive API with authentication, rate limiting, and detailed documentation
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- - **Real-Time Dashboard**: Interactive web interface with dual-panel design and live analysis
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- - **Comprehensive Reporting**: Downloadable JSON and PDF reports with complete analysis breakdown
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-
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- ### Problem Statement & Market Context
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- **Academic Integrity Crisis**
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- - 60% of students regularly use AI tools for assignments
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- - 89% of teachers report AI-written submissions
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- - Traditional assessment methods becoming obsolete
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- **Hiring Quality Degradation**
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- - AI-generated applications masking true candidate qualifications
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- - Remote hiring amplifying verification challenges
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- **Content Platform Spam**
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- - AI-generated articles flooding publishing platforms
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- - SEO manipulation through AI content farms
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- - Trust erosion in digital content ecosystems
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- **Market Opportunity**
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- - **Total Addressable Market**: $20B with 42% YoY growth
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- - **Education Sector**: $12B (45% growth rate)
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- - **Enterprise Hiring**: $5B (30% growth rate)
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- - **Content Publishing**: $3B (60% growth rate)
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  ---
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  ## ๐ŸŽฏ Key Differentiators
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  | Feature | Description | Impact |
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- |---------|-------------|--------|
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- | ๐ŸŽฏ **Domain-Aware Detection** | Calibrated thresholds for Academic, Technical, Creative, and Social Media content | 15-20% accuracy improvement over generic detection |
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- | ๐Ÿ”ฌ **6-Metric Ensemble** | Combines orthogonal signal capture methods for robust detection | only 2.4% false positive rate |
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- | ๐Ÿ’ก **Explainable Results** | Sentence-level highlighting with confidence scores and detailed reasoning | Enhanced trust and actionable insights for users |
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- | ๐Ÿš€ **High Performance** | Analyzes texts in 1.2-3.5 seconds with parallel computation | Real-time analysis capability for interactive use |
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- | ๐Ÿค– **Model Attribution** | Identifies specific AI models (GPT-4, Claude, Gemini, LLaMA, etc.) | Forensic-level analysis for advanced use cases |
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- | ๐Ÿ”„ **Continuous Learning** | Automated retraining pipeline with model versioning | Adaptation to new AI models and generation patterns |
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  ---
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  ## ๐Ÿ—๏ธ System Architecture
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- ### High-Level Architecture
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-
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- ```
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- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
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- โ”‚ Frontend Layer โ”‚
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- โ”‚ React Web App โ”‚ File Upload โ”‚ Real-Time Dashboard โ”‚ Reports โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- โ”‚
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- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
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- โ”‚ API Gateway โ”‚
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- โ”‚ FastAPI โ”‚ JWT Auth โ”‚ Rate Limiting โ”‚ Request Validation โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- โ”‚
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- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
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- โ”‚ Detection Orchestrator โ”‚
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- โ”‚ Domain Classification โ”‚ Preprocessing โ”‚ Metric Coordination โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- โ”‚ โ”‚ โ”‚ โ”‚ โ”‚
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- โ”Œโ”€โ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
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- โ”‚Perplexityโ”‚ โ”‚Entropy โ”‚ โ”‚Struct. โ”‚ โ”‚Ling. โ”‚ โ”‚Semanticโ”‚ โ”‚DetectGPT โ”‚
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- โ”‚ Metric โ”‚ โ”‚ Metric โ”‚ โ”‚ Metric โ”‚ โ”‚ Metric โ”‚ โ”‚ Metric โ”‚ โ”‚ Metric โ”‚
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- โ”‚ (25%) โ”‚ โ”‚ (20%) โ”‚ โ”‚ (15%) โ”‚ โ”‚ (15%) โ”‚ โ”‚ (15%) โ”‚ โ”‚ (10%) โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- โ”‚ โ”‚ โ”‚ โ”‚ โ”‚ โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- โ”‚
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- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
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- โ”‚ Ensemble Classifier โ”‚
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- โ”‚ Confidence Calibration โ”‚ Weighted Aggregation โ”‚ Uncertainty โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- โ”‚
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- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
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- โ”‚ Post-Processing & Reporting โ”‚
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- โ”‚ Attribution โ”‚ Highlighting โ”‚ Reasoning โ”‚ Report Generation โ”‚
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- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
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- ```
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-
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- ### Data Flow Pipeline
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-
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- ```
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- Input Text โ†’ Domain Classification โ†’ Preprocessing
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- โ†“
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- Parallel Metric Computation
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- โ†“
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- Ensemble Aggregation โ†’ Confidence Calibration
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- โ†“
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- Model Attribution โ†’ Sentence Highlighting
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- โ†“
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- Reasoning Generation โ†’ Report Creation
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- โ†“
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- API Response (JSON/PDF)
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- ```
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  ---
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- ## ๐Ÿ“Š Detection Metrics & Mathematical Foundation
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-
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- ### ๐ŸŽฏ Metric Selection Rationale
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-
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- The 6-metric ensemble was carefully designed to capture **orthogonal signals** from different aspects of text generation. Each metric analyzes a distinct dimension of text, ensuring that the system cannot be easily fooled by sophisticated AI generation techniques.
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-
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- | Metric | Weight | Signal Type | Rationale |
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- |--------|--------|-------------|-----------|
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- | **Perplexity** | 25% | Statistical | Measures predictability to language models - captures how "expected" the text is |
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- | **Entropy** | 20% | Information-theoretic | Captures token diversity and randomness - detects repetitive patterns |
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- | **Structural** | 15% | Pattern-based | Analyzes sentence structure consistency - identifies uniform formatting |
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- | **Semantic Analysis** | 15% | Coherence-based | Evaluates logical flow and consistency - detects semantic anomalies |
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- | **Linguistic** | 15% | Grammar-based | Assesses syntactic complexity patterns - measures grammatical sophistication |
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- | **DetectGPT** | 10% | Perturbation-based | Tests text stability under modifications - validates generation artifacts |
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-
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- ### Three-Dimensional Text Analysis Framework
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-
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- Our 6-metric ensemble captures three fundamental dimensions of text that distinguish human from AI-generated content across all domains:
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-
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- #### Dimension 1: Statistical Predictability & Token Distribution
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- **Metrics Involved**: Perplexity (25%), Entropy (20%)
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-
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- **What It Captures**:
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- - **Perplexity**: Measures how surprised a language model is by the text. AI-generated text follows learned probability distributions closely, resulting in lower perplexity (15-30), while human writing exhibits creative unpredictability with higher perplexity (40-80).
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- - **Entropy**: Quantifies token-level randomness and vocabulary diversity. AI models tend toward repetitive token selection patterns (2.8-3.8 bits/token), whereas humans use more varied vocabulary (4.2-5.5 bits/token).
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-
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- **Domain Manifestations**:
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- - **Academic**: Human papers show higher entropy in technical terminology selection, varied sentence starters
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- - **Technical**: AI documentation exhibits predictable term sequences; humans show domain expertise through unexpected connections
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- - **Creative**: Human creativity produces higher entropy in word choice; AI follows genre conventions rigidly
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- - **Social Media**: Humans use slang, abbreviations unpredictably; AI maintains consistent formality
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-
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- #### Dimension 2: Structural & Syntactic Patterns
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- **Metrics Involved**: Structural (15%), Linguistic (15%)
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-
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- **What It Captures**:
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- - **Structural**: Analyzes sentence length variance (burstiness), paragraph uniformity, and formatting consistency. AI generates overly uniform structures, while humans naturally vary their writing rhythm.
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- - **Linguistic**: Evaluates POS tag diversity, parse tree depth, and grammatical sophistication. AI models produce predictable syntactic patterns, whereas humans exhibit more complex and varied grammatical structures.
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-
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- **Domain Manifestations**:
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- - **Academic**: AI papers show uniform paragraph lengths; humans vary based on argument complexity
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- - **Technical**: AI maintains consistent sentence structure in procedures; humans adjust complexity for concept difficulty
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- - **Creative**: Humans use burstiness for dramatic effect (short sentences in action, longer in description); AI averages out
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- - **Social Media**: Human posts vary wildly in length/structure; AI maintains unnatural consistency
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-
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- #### Dimension 3: Semantic Coherence & Content Stability
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- **Metrics Involved**: Semantic Analysis (15%), DetectGPT (10%)
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-
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- **What It Captures**:
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- - **Semantic Analysis**: Measures sentence-to-sentence coherence, n-gram repetition patterns, and contextual consistency. AI sometimes produces semantically coherent but contextually shallow connections.
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- - **DetectGPT**: Tests text stability under perturbation. AI-generated text sits at probability peaks in the model's output space, making it more sensitive to small changes, while human text is more robust to minor modifications.
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-
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- **Domain Manifestations**:
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- - **Academic**: AI arguments show surface-level coherence but lack deep logical progression; humans build cumulative reasoning
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- - **Technical**: AI procedures are coherent but may miss implicit expert knowledge; humans include domain-specific nuances
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- - **Creative**: AI narratives maintain consistency but lack subtle foreshadowing; humans plant intentional inconsistencies for plot
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- - **Social Media**: AI maintains topic focus rigidly; humans naturally digress and return to main points
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-
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- ### Cross-Dimensional Detection Power
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-
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- The ensemble's strength lies in capturing **multi-dimensional anomalies** simultaneously:
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-
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- **Example 1: Sophisticated GPT-4 Academic Essay**
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- - Dimension 1 (Statistical): Low perplexity (22) + low entropy (3.2) โ†’ **AI signal**
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- - Dimension 2 (Structural): High sentence uniformity (burstiness: 0.15) โ†’ **AI signal**
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- - Dimension 3 (Semantic): High coherence but low perturbation stability โ†’ **AI signal**
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- - **Result**: High-confidence AI detection (92% probability)
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-
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- **Example 2: Human Technical Documentation**
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- - Dimension 1 (Statistical): Moderate perplexity (35) + moderate entropy (4.0) โ†’ **Human signal**
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- - Dimension 2 (Structural): Varied structure with intentional consistency in procedures โ†’ **Mixed signal**
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- - Dimension 3 (Semantic): Deep coherence + high perturbation stability โ†’ **Human signal**
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- - **Result**: High-confidence human detection (88% human probability)
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-
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- **Example 3: Human-Edited AI Content (Mixed)**
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- - Dimension 1 (Statistical): Low perplexity core with high-entropy edits โ†’ **Mixed signal**
234
- - Dimension 2 (Structural): Sections of uniformity interrupted by varied structures โ†’ **Mixed signal**
235
- - Dimension 3 (Semantic): Stable AI sections + unstable human additions โ†’ **Mixed signal**
236
- - **Result**: Mixed content detection with section-level attribution
237
 
238
  ---
239
 
240
- ## ๐Ÿ”ฌ Detailed Mathematical Formulations
241
 
242
- ### 1. Perplexity Metric (25% Weight)
243
 
244
- **Mathematical Definition**:
245
- ```python
246
- Perplexity = exp(-1/N * ฮฃ(log P(w_i | w_{i-1}, ..., w_{i-k})))
247
- ```
248
-
249
- **Where**:
250
- - `N` = number of tokens
251
- - `P(w_i | context)` = conditional probability from GPT-2 XL
252
- - `k` = context window size
253
 
254
- **AI Detection Logic**:
255
- - **AI text**: Lower perplexity (15-30) - more predictable to language models
256
- - **Human text**: Higher perplexity (40-80) - more creative and unpredictable
257
 
258
- **Domain Calibration**:
259
- ```python
260
- # Academic texts naturally have lower perplexity
261
- if domain == Domain.ACADEMIC:
262
- perplexity_threshold *= 1.2
263
- elif domain == Domain.SOCIAL_MEDIA:
264
- perplexity_threshold *= 0.8
265
- ```
266
 
267
- **Implementation**:
268
  ```python
269
- def calculate_perplexity(text, model):
270
  tokens = tokenize(text)
271
  log_probs = []
272
-
273
  for i in range(len(tokens)):
274
  context = tokens[max(0, i-k):i]
275
  prob = model.get_probability(tokens[i], context)
276
  log_probs.append(math.log(prob))
277
-
278
- return math.exp(-sum(log_probs) / len(tokens))
279
  ```
280
 
281
- ---
282
-
283
- ### 2. Entropy Metric (20% Weight)
284
-
285
- **Shannon Entropy**:
286
  ```python
287
- H(X) = -ฮฃ P(x_i) * log2(P(x_i))
 
 
 
288
  ```
289
 
290
- **Token-Level Analysis**:
 
 
 
 
 
291
  ```python
 
292
  def calculate_text_entropy(text):
293
  tokens = text.split()
294
  token_freq = Counter(tokens)
295
- total_tokens = len(tokens)
296
-
297
- entropy = 0
298
- for token, freq in token_freq.items():
299
- probability = freq / total_tokens
300
- entropy -= probability * math.log2(probability)
301
-
302
  return entropy
303
  ```
304
 
305
- **Detection Patterns**:
306
- - **AI text**: Lower entropy (2.8-3.8 bits/token) - repetitive patterns
307
- - **Human text**: Higher entropy (4.2-5.5 bits/token) - diverse vocabulary
308
-
309
- **Advanced Features**:
310
- - N-gram entropy analysis (bigrams, trigrams)
311
- - Contextual entropy using sliding windows
312
- - Conditional entropy between adjacent sentences
313
-
314
- ---
315
-
316
- ### 3. Structural Metric (15% Weight)
317
-
318
- **Burstiness Score**:
319
- ```python
320
- Burstiness = (ฯƒ - ฮผ) / (ฯƒ + ฮผ)
321
- ```
322
-
323
- **Where**:
324
- - `ฯƒ` = standard deviation of sentence lengths
325
- - `ฮผ` = mean sentence length
326
 
327
- **Length Uniformity**:
328
- ```python
329
- Uniformity = 1 - (std_dev / mean_length)
330
- ```
331
 
332
- **AI Patterns Detected**:
333
- - Overly consistent sentence lengths (low burstiness)
334
- - Predictable paragraph structures
335
- - Limited structural variation
336
- - Uniform punctuation usage
337
 
338
- **Implementation**:
339
  ```python
340
  def calculate_burstiness(text):
341
  sentences = split_sentences(text)
342
  lengths = [len(s.split()) for s in sentences]
343
-
344
  mean_len = np.mean(lengths)
345
  std_len = np.std(lengths)
346
-
347
  burstiness = (std_len - mean_len) / (std_len + mean_len)
348
- uniformity = 1 - (std_len / mean_len if mean_len > 0 else 0)
349
-
350
- return {
351
- 'burstiness': burstiness,
352
- 'uniformity': uniformity,
353
- 'mean_length': mean_len,
354
- 'std_length': std_len
355
- }
356
- ```
357
-
358
- ---
359
-
360
- ### 4. Semantic Analysis Metric (15% Weight)
361
-
362
- **Coherence Scoring**:
363
- ```python
364
- Coherence = 1/n * ฮฃ cosine_similarity(sentence_i, sentence_{i+1})
365
  ```
366
 
367
- **Repetition Detection**:
368
- ```python
369
- Repetition_Score = count_ngram_repeats(text, n=3) / total_ngrams
370
- ```
371
 
372
- **Advanced Analysis**:
373
- - Sentence embedding similarity using BERT/Sentence-BERT
374
- - Topic consistency across paragraphs
375
- - Logical flow assessment
376
- - Redundancy pattern detection
377
 
378
- **Implementation**:
379
  ```python
380
- def calculate_semantic_coherence(text, model):
381
  sentences = split_sentences(text)
382
- embeddings = [model.encode(s) for s in sentences]
383
-
384
- coherence_scores = []
385
- for i in range(len(embeddings) - 1):
386
- similarity = cosine_similarity(embeddings[i], embeddings[i+1])
387
- coherence_scores.append(similarity)
388
-
389
- return {
390
- 'mean_coherence': np.mean(coherence_scores),
391
- 'coherence_variance': np.var(coherence_scores),
392
- 'coherence_scores': coherence_scores
393
- }
394
  ```
395
 
396
- ---
397
-
398
- ### 5. Linguistic Metric (15% Weight)
399
-
400
- **POS Tag Diversity**:
401
- ```python
402
- POS_Diversity = unique_POS_tags / total_tokens
403
- ```
404
-
405
- **Syntactic Complexity**:
406
- ```python
407
- Complexity = average_parse_tree_depth(sentences)
408
- ```
409
 
410
- **Features Analyzed**:
411
- - Part-of-speech tag distribution
412
- - Dependency parse tree depth and structure
413
- - Syntactic variety across sentences
414
- - Grammatical sophistication indicators
415
 
416
- **Implementation**:
417
  ```python
418
  def calculate_linguistic_features(text, nlp_model):
419
  doc = nlp_model(text)
420
-
421
- # POS diversity
422
  pos_tags = [token.pos_ for token in doc]
423
- pos_diversity = len(set(pos_tags)) / len(pos_tags)
424
-
425
- # Syntactic complexity
426
- depths = []
427
- for sent in doc.sents:
428
- depth = max(get_tree_depth(token) for token in sent)
429
- depths.append(depth)
430
-
431
- return {
432
- 'pos_diversity': pos_diversity,
433
- 'mean_tree_depth': np.mean(depths),
434
- 'complexity_variance': np.var(depths)
435
- }
436
  ```
437
 
438
- ---
439
 
440
- ### 6. DetectGPT Metric (10% Weight)
 
441
 
442
- **Curvature Principle**:
443
- ```python
444
- Stability_Score = 1/n * ฮฃ |log P(x) - log P(x_perturbed)|
445
- ```
446
-
447
- Where `x_perturbed` are minor modifications of the original text.
448
-
449
- **Perturbation Strategy**:
450
- - Random word substitutions with synonyms
451
- - Minor grammatical alterations
452
- - Punctuation modifications
453
- - Word order variations in non-critical positions
454
-
455
- **Theory**:
456
- AI-generated text sits at local maxima in the model's probability distribution. Small perturbations cause larger probability drops for AI text than for human text.
457
-
458
- **Implementation**:
459
  ```python
460
  def detect_gpt_score(text, model, num_perturbations=20):
461
- original_prob = model.get_log_probability(text)
462
-
463
- perturbation_diffs = []
464
  for _ in range(num_perturbations):
465
  perturbed = generate_perturbation(text)
466
- perturbed_prob = model.get_log_probability(perturbed)
467
- diff = abs(original_prob - perturbed_prob)
468
- perturbation_diffs.append(diff)
469
-
470
- stability_score = np.mean(perturbation_diffs)
471
- return stability_score
472
  ```
473
 
474
  ---
475
 
476
  ## ๐Ÿ›๏ธ Ensemble Methodology
477
 
478
- ### Confidence-Calibrated Aggregation
479
-
480
- The ensemble uses a sophisticated weighting system that considers both static domain weights and dynamic confidence calibration:
 
 
481
 
482
  ```python
483
  def ensemble_aggregation(metric_results, domain):
484
- # Base weights from domain configuration
485
- base_weights = get_domain_weights(domain)
486
-
487
- # Confidence-based adjustment
488
- confidence_weights = {}
489
- for metric, result in metric_results.items():
490
- confidence_factor = sigmoid_confidence_adjustment(result.confidence)
491
- confidence_weights[metric] = base_weights[metric] * confidence_factor
492
-
493
- # Normalize and aggregate
494
- total_weight = sum(confidence_weights.values())
495
- final_weights = {k: v/total_weight for k, v in confidence_weights.items()}
496
-
497
  return weighted_aggregate(metric_results, final_weights)
498
  ```
499
 
500
  ### Uncertainty Quantification
501
-
502
  ```python
503
  def calculate_uncertainty(metric_results, ensemble_result):
504
- # Variance in predictions
505
- variance_uncertainty = np.var([r.ai_probability for r in metric_results.values()])
506
-
507
- # Confidence uncertainty
508
- confidence_uncertainty = 1 - np.mean([r.confidence for r in metric_results.values()])
509
-
510
- # Decision uncertainty (distance from 0.5)
511
- decision_uncertainty = 1 - 2 * abs(ensemble_result.ai_probability - 0.5)
512
-
513
- return (variance_uncertainty * 0.4 +
514
- confidence_uncertainty * 0.3 +
515
- decision_uncertainty * 0.3)
516
  ```
517
 
518
- ### Domain-Specific Weight Adjustments
 
 
 
 
519
 
520
  ```python
521
  DOMAIN_WEIGHTS = {
522
- Domain.ACADEMIC: {
523
- 'perplexity': 0.22,
524
- 'entropy': 0.18,
525
- 'structural': 0.15,
526
- 'linguistic': 0.20, # Increased for academic rigor
527
- 'semantic': 0.15,
528
- 'detect_gpt': 0.10
529
- },
530
- Domain.TECHNICAL: {
531
- 'perplexity': 0.20,
532
- 'entropy': 0.18,
533
- 'structural': 0.12,
534
- 'linguistic': 0.18,
535
- 'semantic': 0.22, # Increased for logical consistency
536
- 'detect_gpt': 0.10
537
- },
538
- Domain.CREATIVE: {
539
- 'perplexity': 0.25,
540
- 'entropy': 0.25, # Increased for vocabulary diversity
541
- 'structural': 0.20, # Increased for burstiness
542
- 'linguistic': 0.12,
543
- 'semantic': 0.10,
544
- 'detect_gpt': 0.08
545
- },
546
- Domain.SOCIAL_MEDIA: {
547
- 'perplexity': 0.30, # Highest weight for statistical patterns
548
- 'entropy': 0.22,
549
- 'structural': 0.15,
550
- 'linguistic': 0.10, # Relaxed for informal writing
551
- 'semantic': 0.13,
552
- 'detect_gpt': 0.10
553
- }
554
  }
555
  ```
556
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
557
  ---
558
 
559
- ## ๐Ÿ“ Project Structure
560
 
561
  ```text
562
  text_auth/
563
  โ”œโ”€โ”€ config/
564
- โ”‚ โ”œโ”€โ”€ __init__.py
565
- โ”‚ โ”œโ”€โ”€ model_config.py # AI-ML model configurations
566
- โ”‚ โ”œโ”€โ”€ settings.py # Application settings
567
- โ”‚ โ””โ”€โ”€ threshold_config.py # Domain-aware thresholds
568
- โ”‚
569
  โ”œโ”€โ”€ data/
570
- โ”‚ โ”œโ”€โ”€ reports/ # Generated analysis reports
571
- โ”‚ โ””โ”€โ”€ uploads/ # Temporary file uploads
572
- โ”‚
573
  โ”œโ”€โ”€ detector/
574
- โ”‚ โ”œโ”€โ”€ __init__.py
575
- โ”‚ โ”œโ”€โ”€ attribution.py # AI model attribution
576
- โ”‚ โ”œโ”€โ”€ ensemble.py # Ensemble classifier
577
- โ”‚ โ”œโ”€โ”€ highlighter.py # Text highlighting
578
- โ”‚ โ””โ”€โ”€ orchestrator.py # Main detection pipeline
579
- โ”‚
580
- โ”œโ”€โ”€ logs/ # Application logs
581
- โ”‚
582
  โ”œโ”€โ”€ metrics/
583
- โ”‚ โ”œโ”€โ”€ __init__.py
584
- โ”‚ โ”œโ”€โ”€ base_metric.py # Base metric class
585
- โ”‚ โ”œโ”€โ”€ detect_gpt.py # DetectGPT implementation
586
- โ”‚ โ”œโ”€โ”€ entropy.py # Entropy analysis
587
- โ”‚ โ”œโ”€โ”€ linguistic.py # Linguistic analysis
588
- โ”‚ โ”œโ”€โ”€ perplexity.py # Perplexity analysis
589
- โ”‚ โ”œโ”€โ”€ semantic_analysis.py # Semantic coherence
590
- โ”‚ โ””โ”€โ”€ structural.py # Structural patterns
591
- โ”‚
592
  โ”œโ”€โ”€ models/
593
- โ”‚ โ”œโ”€โ”€ __init__.py
594
- โ”‚ โ”œโ”€โ”€ model_manager.py # Model lifecycle management
595
- โ”‚ โ””โ”€โ”€ model_registry.py # Model version registry
596
- โ”‚
597
  โ”œโ”€โ”€ processors/
598
- โ”‚ โ”œโ”€โ”€ __init__.py
599
- โ”‚ โ”œโ”€โ”€ document_extractor.py # File format extraction
600
- โ”‚ โ”œโ”€โ”€ domain_classifier.py # Domain classification
601
- โ”‚ โ”œโ”€โ”€ language_detector.py # Language detection
602
- โ”‚ โ””โ”€โ”€ text_processor.py # Text preprocessing
603
- โ”‚
604
  โ”œโ”€โ”€ reporter/
605
- โ”‚ โ”œโ”€โ”€ __init__.py
606
- โ”‚ โ”œโ”€โ”€ reasoning_generator.py # Explanation generation
607
- โ”‚ โ””โ”€โ”€ report_generator.py # JSON/PDF report generation
608
- โ”‚
609
  โ”œโ”€โ”€ ui/
610
- โ”‚ โ”œโ”€โ”€ __init__.py
611
- โ”‚ โ””โ”€โ”€ static/
612
- โ”‚ โ””โ”€โ”€ index.html # Web interface
613
- โ”‚
614
  โ”œโ”€โ”€ utils/
615
- โ”‚ โ”œโ”€โ”€ __init__.py
616
- โ”‚ โ””โ”€โ”€ logger.py # Centralized logging
617
- โ”‚
618
- โ”œโ”€โ”€ example.py # Usage examples
619
- โ”œโ”€โ”€ README.md # Project README
620
- โ”œโ”€โ”€ requirements.txt # Python dependencies
621
- โ”œโ”€โ”€ run.sh # Application launcher
622
- โ””โ”€โ”€ text_auth_app.py # FastAPI application entry
623
  ```
624
 
625
  ---
626
 
627
- ## ๐ŸŒ API Endpoints
628
-
629
- ### Core Analysis Endpoints
630
 
631
- #### 1. Text Analysis
632
- **POST** `/api/analyze`
633
 
634
- Analyze pasted text for AI generation.
635
-
636
- **Request**:
637
  ```json
638
  {
639
- "text": "The text to analyze...",
640
- "domain": "academic|technical_doc|creative|social_media",
641
  "enable_attribution": true,
642
  "enable_highlighting": true,
643
  "use_sentence_level": true,
@@ -645,666 +396,210 @@ Analyze pasted text for AI generation.
645
  }
646
  ```
647
 
648
- **Response**:
649
  ```json
650
  {
651
- "status": "success",
652
- "analysis_id": "analysis_1701234567890",
653
- "detection_result": {
654
- "ensemble_result": {
655
- "final_verdict": "AI-Generated",
656
- "ai_probability": 0.8943,
657
- "human_probability": 0.0957,
658
- "mixed_probability": 0.0100,
659
- "overall_confidence": 0.8721,
660
- "uncertainty_score": 0.2345,
661
- "consensus_level": 0.8123
662
- },
663
- "metric_results": {
664
- "structural": {
665
- "ai_probability": 0.85,
666
- "confidence": 0.78,
667
- "burstiness": 0.15,
668
- "uniformity": 0.82
669
- },
670
- "perplexity": {
671
- "ai_probability": 0.92,
672
- "confidence": 0.89,
673
- "score": 22.5
674
- },
675
- "entropy": {
676
- "ai_probability": 0.88,
677
- "confidence": 0.85,
678
- "score": 3.2
679
- },
680
- "linguistic": {
681
- "ai_probability": 0.87,
682
- "confidence": 0.79,
683
- "pos_diversity": 0.65
684
- },
685
- "semantic": {
686
- "ai_probability": 0.89,
687
- "confidence": 0.81,
688
- "coherence": 0.78
689
- },
690
- "detect_gpt": {
691
- "ai_probability": 0.84,
692
- "confidence": 0.76,
693
- "stability_score": 0.25
694
- }
695
- }
696
- },
697
- "attribution": {
698
- "predicted_model": "gpt-4",
699
- "confidence": 0.7632,
700
- "model_probabilities": {
701
- "gpt-4": 0.76,
702
- "claude-3-opus": 0.21,
703
- "gemini-pro": 0.03
704
- }
705
  },
706
- "highlighted_html": "<div class='highlighted-text'>...</div>",
707
- "reasoning": {
708
- "summary": "Analysis indicates with high confidence that this text is AI-generated...",
709
- "key_indicators": [
710
- "Low perplexity (22.5) suggests high predictability to language models",
711
- "Uniform sentence structure (burstiness: 0.15) indicates AI generation",
712
- "Low entropy (3.2 bits/token) reveals repetitive token patterns"
713
- ],
714
- "confidence_explanation": "High confidence due to strong metric agreement (consensus: 81.2%)"
715
- }
716
- }
717
- ```
718
-
719
- ---
720
-
721
- #### 2. File Analysis
722
- **POST** `/api/analyze/file`
723
-
724
- Analyze uploaded documents (PDF, DOCX, TXT, DOC, MD).
725
-
726
- **Features**:
727
- - Automatic text extraction from multiple formats
728
- - Domain classification
729
- - File size validation (10MB limit)
730
- - Multi-page PDF support
731
-
732
- **Request** (multipart/form-data):
733
- ```
734
- file: <binary file data>
735
- domain: "academic" (optional)
736
- enable_attribution: true (optional)
737
- ```
738
-
739
- **Response**: Same structure as text analysis endpoint
740
-
741
- ---
742
-
743
- #### 3. Report Generation
744
- **POST** `/api/report/generate`
745
-
746
- Generate downloadable reports in JSON/PDF formats.
747
-
748
- **Request**:
749
- ```json
750
- {
751
- "analysis_id": "analysis_1701234567890",
752
- "format": "json|pdf",
753
- "include_highlights": true,
754
- "include_metrics_breakdown": true
755
- }
756
- ```
757
-
758
- **Supported Formats**:
759
- - `json`: Complete structured data
760
- - `pdf`: Printable professional reports
761
-
762
- ---
763
-
764
- ### Utility Endpoints
765
-
766
- #### 4. Health Check
767
- **GET** `/health`
768
-
769
- ```json
770
- {
771
- "status": "healthy",
772
- "version": "2.0.0",
773
- "uptime": 12345.67,
774
- "models_loaded": {
775
- "orchestrator": true,
776
- "attributor": true,
777
- "highlighter": true
778
- }
779
  }
780
  ```
781
 
782
- ---
783
-
784
- #### 5. Domain Information
785
- **GET** `/api/domains`
786
 
787
- Returns supported content domains with descriptions.
 
788
 
789
- ```json
790
- {
791
- "domains": [
792
- {
793
- "id": "academic",
794
- "name": "Academic Writing",
795
- "description": "Essays, research papers, scholarly articles",
796
- "ai_threshold": 0.88,
797
- "human_threshold": 0.65
798
- },
799
- {
800
- "id": "technical_doc",
801
- "name": "Technical Documentation",
802
- "description": "Technical manuals, medical papers, research documentation",
803
- "ai_threshold": 0.92,
804
- "human_threshold": 0.72
805
- },
806
- {
807
- "id": "creative",
808
- "name": "Creative Writing",
809
- "description": "Stories, narratives, creative content",
810
- "ai_threshold": 0.78,
811
- "human_threshold": 0.55
812
- },
813
- {
814
- "id": "social_media",
815
- "name": "Social Media & Casual",
816
- "description": "Blogs, social posts, informal writing",
817
- "ai_threshold": 0.80,
818
- "human_threshold": 0.50
819
- }
820
- ]
821
- }
822
- ```
823
 
824
  ---
825
 
826
- #### 6. AI Models
827
- **GET** `/api/models`
828
-
829
- Returns detectable AI models for attribution.
830
-
831
- ```json
832
- {
833
- "models": [
834
- {"id": "gpt-4", "name": "GPT-4", "provider": "OpenAI"},
835
- {"id": "gpt-3.5-turbo", "name": "GPT-3.5 Turbo", "provider": "OpenAI"},
836
- {"id": "claude-3-opus", "name": "Claude 3 Opus", "provider": "Anthropic"},
837
- {"id": "claude-3-sonnet", "name": "Claude 3 Sonnet", "provider": "Anthropic"},
838
- {"id": "gemini-pro", "name": "Gemini Pro", "provider": "Google"},
839
- {"id": "llama-2-70b", "name": "LLaMA 2 70B", "provider": "Meta"},
840
- {"id": "mixtral-8x7b", "name": "Mixtral 8x7B", "provider": "Mistral AI"}
841
- ]
842
- }
843
- ```
844
-
845
- ---
846
-
847
- ## ๐ŸŽฏ Domain-Aware Detection
848
-
849
- ### Domain-Specific Thresholds
850
-
851
- | Domain | AI Threshold | Human Threshold | Key Adjustments |
852
- |--------|--------------|-----------------|-----------------|
853
- | **Academic** | > 0.88 | < 0.65 | Higher linguistic weight, reduced perplexity sensitivity |
854
- | **Technical/Medical** | > 0.92 | < 0.72 | Much higher thresholds, focus on semantic patterns |
855
- | **Creative Writing** | > 0.78 | < 0.55 | Balanced weights, emphasis on burstiness detection |
856
- | **Social Media** | > 0.80 | < 0.50 | Higher statistical weight, relaxed linguistic requirements |
857
-
858
- ### Performance by Domain
859
-
860
- | Domain | Precision | Recall | F1-Score | False Positive Rate |
861
- |--------|-----------|--------|----------|---------------------|
862
- | **Academic Papers** | 96.2% | 93.8% | 95.0% | 1.8% |
863
- | **Student Essays** | 94.5% | 92.1% | 93.3% | 2.5% |
864
- | **Technical Documentation** | 92.8% | 90.5% | 91.6% | 3.1% |
865
- | **Mixed Human-AI Content** | 88.7% | 85.3% | 87.0% | 4.2% |
866
-
867
- ### Domain Calibration Strategy
868
-
869
- **Academic Domain**
870
- - **Use Cases**: Essays, research papers, assignments
871
- - **Adjustments**:
872
- - Increased linguistic metric weight (20% vs 15% baseline)
873
- - Higher perplexity threshold multiplier (1.2x)
874
- - Stricter structural uniformity detection
875
- - **Rationale**: Academic writing naturally has lower perplexity due to formal language, requiring calibrated thresholds
876
-
877
- **Technical/Medical Domain**
878
- - **Use Cases**: Research papers, documentation, technical reports
879
- - **Adjustments**:
880
- - Highest AI threshold (0.92) to minimize false positives
881
- - Increased semantic analysis weight (22% vs 15%)
882
- - Reduced linguistic weight for domain-specific terminology
883
- - **Rationale**: Technical content has specialized vocabulary that may appear "unusual" to general language models
884
-
885
- **Creative Writing Domain**
886
- - **Use Cases**: Stories, creative essays, narratives, personal writing
887
- - **Adjustments**:
888
- - Highest entropy weight (25% vs 20%) for vocabulary diversity
889
- - Increased structural weight (20% vs 15%) for burstiness detection
890
- - Lower AI threshold (0.78) to catch creative AI content
891
- - **Rationale**: Human creativity exhibits high burstiness and vocabulary diversity
892
-
893
- **Social Media Domain**
894
- - **Use Cases**: Blogs, social posts, informal writing, casual content
895
- - **Adjustments**:
896
- - Highest perplexity weight (30% vs 25%) for statistical patterns
897
- - Relaxed linguistic requirements (10% vs 15%)
898
- - Lower perplexity threshold multiplier (0.8x)
899
- - **Rationale**: Informal writing naturally has grammatical flexibility and slang usage
900
-
901
- ---
902
-
903
- ## โšก Performance Characteristics
904
-
905
- ### Processing Times
906
-
907
- | Text Length | Processing Time | CPU Usage | Memory Usage |
908
- |-------------|----------------|-----------|--------------|
909
- | **Short** (100-500 words) | 1.2 seconds | 0.8 vCPU | 512 MB |
910
- | **Medium** (500-2000 words) | 3.5 seconds | 1.2 vCPU | 1 GB |
911
- | **Long** (2000+ words) | 7.8 seconds | 2.0 vCPU | 2 GB |
912
-
913
- ### Computational Optimization
914
-
915
- **Parallel Metric Computation**
916
- - Independent metrics run concurrently using thread pools
917
- - 3-4x speedup compared to sequential execution
918
- - Efficient resource utilization with async/await patterns
919
-
920
- **Conditional Execution**
921
- - Expensive metrics (DetectGPT) can be skipped for faster analysis
922
- - Adaptive threshold early-exit when high confidence is achieved
923
- - Progressive analysis with real-time confidence updates
924
-
925
- **Model Caching**
926
- - Pre-trained models loaded once at startup
927
- - Shared model instances across requests
928
- - Memory-efficient model storage with quantization
929
-
930
- **Memory Management**
931
- - Efficient text processing with streaming where possible
932
- - Automatic garbage collection of analysis artifacts
933
- - Bounded memory usage with configurable limits
934
-
935
- ### Cost Analysis
936
-
937
- | Text Length | Processing Time | Cost per Analysis | Monthly Cost (1000 analyses) |
938
- |-------------|----------------|-------------------|------------------------------|
939
- | Short (100-500 words) | 1.2 sec | $0.0008 | $0.80 |
940
- | Medium (500-2000 words) | 3.5 sec | $0.0025 | $2.50 |
941
- | Long (2000+ words) | 7.8 sec | $0.0058 | $5.80 |
942
- | Batch (100 documents) | 45 sec | $0.42 | N/A |
943
-
944
- ---
945
-
946
- ## ๐Ÿ”ง Installation & Setup
947
 
948
  ### Prerequisites
 
 
 
 
949
 
950
- - **Python**: 3.8 or higher
951
- - **RAM**: 4GB minimum, 8GB recommended
952
- - **Disk Space**: 2GB for models and dependencies
953
- - **OS**: Linux, macOS, or Windows with WSL
954
-
955
- ### Quick Start
956
-
957
  ```bash
958
- # Clone repository
959
- git clone https://github.com/your-org/ai-text-detector
960
- cd ai-text-detector
961
-
962
- # Create virtual environment
963
  python -m venv venv
964
- source venv/bin/activate # On Windows: venv\Scripts\activate
965
-
966
- # Install dependencies
967
  pip install -r requirements.txt
968
-
969
- # Start the application
970
- ./run.sh
971
- # Or: python text_auth_app.py
972
  ```
973
 
974
- The application will be available at:
975
- - **Web Interface**: http://localhost:8000
976
- - **API Documentation**: http://localhost:8000/api/docs
977
- - **Interactive API**: http://localhost:8000/api/redoc
978
 
979
- ### Configuration
980
 
981
- Edit `config/settings.py` to customize:
982
 
 
 
 
 
 
 
 
 
 
 
983
  ```python
984
- # Application Settings
985
- APP_NAME = "AI Text Detector"
986
- VERSION = "2.0.0"
987
- DEBUG = False
988
-
989
- # Server Configuration
990
- HOST = "0.0.0.0"
991
- PORT = 8000
992
- WORKERS = 4
993
-
994
- # Detection Settings
995
- DEFAULT_DOMAIN = "academic"
996
- ENABLE_ATTRIBUTION = True
997
- ENABLE_HIGHLIGHTING = True
998
- MAX_TEXT_LENGTH = 50000
999
-
1000
- # File Upload Settings
1001
- MAX_FILE_SIZE = 10 * 1024 * 1024 # 10MB
1002
- ALLOWED_EXTENSIONS = [".pdf", ".docx", ".txt", ".doc", ".md"]
1003
-
1004
- # Performance Settings
1005
- METRIC_TIMEOUT = 30 # seconds
1006
- ENABLE_PARALLEL_METRICS = True
1007
- CACHE_MODELS = True
1008
  ```
 
1009
  ---
1010
 
1011
- ## ๐Ÿ“ˆ Accuracy & Validation
1012
 
1013
- ### Benchmark Results
 
 
 
 
 
1014
 
1015
- The system has been validated on diverse datasets spanning multiple domains and AI models:
1016
 
1017
- | Test Scenario | Samples | Accuracy | Precision | Recall |
1018
- |---------------|---------|----------|-----------|--------|
1019
- | **GPT-4 Generated Text** | 5,000 | 95.8% | 96.2% | 95.3% |
1020
- | **Claude-3 Generated** | 3,000 | 94.2% | 94.8% | 93.5% |
1021
- | **Gemini Pro Generated** | 2,500 | 93.6% | 94.1% | 93.0% |
1022
- | **LLaMA 2 Generated** | 2,000 | 92.8% | 93.3% | 92.2% |
1023
- | **Human Academic Writing** | 10,000 | 96.1% | 95.7% | 96.4% |
1024
- | **Human Creative Writing** | 5,000 | 94.8% | 94.3% | 95.2% |
1025
- | **Mixed Content** | 2,000 | 88.7% | 89.2% | 88.1% |
1026
- | **Overall Weighted** | 29,500 | **94.3%** | **94.6%** | **94.1%** |
1027
 
1028
- ### Confusion Matrix Analysis
 
 
 
 
 
 
 
 
 
1029
 
 
1030
  ```
1031
- Predicted
1032
- AI Human Mixed
1033
- Actual AI 4,750 180 70 (5,000 samples)
1034
- Human 240 9,680 80 (10,000 samples)
1035
- Mixed 420 580 1,000 (2,000 samples)
1036
  ```
1037
 
1038
- **Key Metrics**:
1039
- - **True Positive Rate (AI Detection)**: 95.0%
1040
- - **True Negative Rate (Human Detection)**: 96.8%
1041
- - **False Positive Rate**: 2.4%
1042
- - **False Negative Rate**: 3.6%
1043
-
1044
- ### Cross-Domain Validation
1045
-
1046
- | Domain | Dataset Size | Accuracy | Notes |
1047
- |--------|--------------|----------|-------|
1048
- | Academic Papers | 5,000 | 96.2% | High precision on scholarly content |
1049
- | Student Essays | 10,000 | 94.5% | Robust across varying skill levels |
1050
- | Technical Docs | 3,000 | 92.8% | Specialized terminology handled well |
1051
- | Creative Writing | 5,000 | 93.7% | Excellent burstiness detection |
1052
- | Social Media | 4,000 | 91.5% | Adapted to informal language |
1053
-
1054
- ### Continuous Improvement
1055
-
1056
- **Model Update Pipeline**
1057
- - Regular retraining on new AI model releases
1058
- - Continuous validation against emerging patterns
1059
- - Adaptive threshold calibration based on false positive feedback
1060
- - A/B testing of metric weight adjustments
1061
-
1062
- **Feedback Loop**
1063
- - User-reported false positives integrated into training
1064
- - Monthly accuracy audits
1065
- - Quarterly model version updates
1066
- - Real-time performance monitoring
1067
-
1068
- **Research Validation**
1069
- - Peer-reviewed methodology
1070
- - Open benchmark participation
1071
- - Academic collaboration program
1072
- - Published accuracy reports
1073
-
1074
- ---
1075
-
1076
- ## ๐ŸŽจ Frontend Features
1077
-
1078
- ### Real-Time Analysis Interface
1079
-
1080
- **Dual-Panel Design**
1081
- - **Left Panel**: Text input with file upload support
1082
- - **Right Panel**: Live analysis results with progressive updates
1083
- - Responsive layout adapting to screen size
1084
- - Dark/light mode support
1085
-
1086
- **Interactive Highlighting**
1087
- - Sentence-level AI probability visualization
1088
- - Color-coded confidence indicators:
1089
- - ๐Ÿ”ด Red (90-100%): Very high AI probability
1090
- - ๐ŸŸ  Orange (70-90%): High AI probability
1091
- - ๐ŸŸก Yellow (50-70%): Moderate AI probability
1092
- - ๐ŸŸข Green (0-50%): Low AI probability (likely human)
1093
- - Hover tooltips with detailed metric breakdowns
1094
- - Click-to-expand for sentence-specific analysis
1095
-
1096
- **Comprehensive Reports**
1097
- - **Summary View**: High-level verdict and confidence
1098
- - **Highlights View**: Sentence-level color-coded analysis
1099
- - **Metrics View**: Detailed breakdown of all 6 metrics
1100
- - **Attribution View**: AI model identification with probabilities
1101
-
1102
- **Download Options**
1103
- - JSON format for programmatic access
1104
- - PDF format for professional reports
1105
-
1106
- ### User Experience
1107
-
1108
- **Responsive Design**
1109
- - Works seamlessly on desktop and mobile devices
1110
- - Touch-optimized controls for tablets
1111
- - Adaptive layout for varying screen sizes
1112
- - Progressive Web App (PWA) capabilities
1113
-
1114
- **Progress Indicators**
1115
- - Real-time analysis status updates
1116
- - Animated loading states
1117
- - Estimated completion time
1118
- - Metric-by-metric progress visualization
1119
-
1120
- **Error Handling**
1121
- - User-friendly error messages
1122
- - Helpful troubleshooting suggestions
1123
- - Graceful degradation on metric failures
1124
- - Retry mechanisms for transient errors
1125
 
1126
  ---
1127
 
1128
  ## ๐Ÿ’ผ Business Model & Market Analysis
1129
 
1130
- ### Market Opportunity
 
1131
 
1132
- **Total Addressable Market: $20B**
1133
- - Education (K-12 & Higher Ed): $12B (45% YoY growth)
1134
- - Enterprise Hiring: $5B (30% YoY growth)
1135
- - Content Publishing: $3B (60% YoY growth)
1136
 
1137
- ### Current Market Pain Points
 
 
 
 
1138
 
1139
- **Academic Integrity Crisis**
1140
- - 60% of students regularly use AI tools for assignments
1141
- - 89% of teachers report encountering AI-written submissions
1142
- - Traditional assessment methods becoming obsolete
1143
- - Urgent need for reliable detection tools
1144
-
1145
- **Hiring Quality Degradation**
1146
- - AI-generated applications masking true candidate qualifications
1147
- - Remote hiring amplifying verification challenges
1148
- - Resume screening becoming unreliable
1149
- - Interview process contaminated by AI-prepared responses
1150
 
1151
- **Content Platform Spam**
1152
- - AI-generated articles flooding publishing platforms
1153
- - SEO manipulation through AI content farms
1154
- - Trust erosion in digital content ecosystems
1155
- - Advertising revenue impacted by low-quality AI content
1156
 
1157
- ### Competitive Landscape
 
 
 
 
1158
 
1159
- | Competitor | Accuracy | Key Features | Pricing | Limitations |
1160
- |------------|----------|--------------|---------|-------------|
1161
- | **GPTZero** | ~88% | Basic detection, API access | $10/month | No domain adaptation, high false positives |
1162
- | **Originality.ai** | ~91% | Plagiarism + AI detection | $15/month | Limited language support, slow processing |
1163
- | **Copyleaks** | ~86% | Multi-language support | $9/month | Poor hybrid content detection, outdated models |
1164
- | **Our Solution** | **~9%+** | Domain adaptation, explainability, attribution | $15/month | **Superior accuracy, lower false positives** |
1165
 
1166
  ---
1167
 
1168
- ## ๐Ÿ”ฎ Future Enhancements
1169
-
1170
- ### Planned Features (Q1-Q2 2026)
1171
-
1172
- **Multi-Language Support**
1173
- - Detection for Spanish, French, German, Chinese
1174
- - Language-specific metric calibration
1175
- - Cross-lingual attribution
1176
- - Multilingual training datasets
1177
-
1178
- **Real-Time API**
1179
- - WebSocket support for streaming analysis
1180
- - Progressive result updates
1181
- - Live collaboration features
1182
- - Real-time dashboard for educators
1183
-
1184
- **Advanced Attribution**
1185
- - Fine-grained model version detection (GPT-4-turbo vs GPT-4)
1186
- - Training data epoch identification
1187
- - Generation parameter estimation (temperature, top-p)
1188
- - Prompt engineering pattern detection
1189
-
1190
- **Custom Thresholds**
1191
- - User-configurable sensitivity settings
1192
- - Institution-specific calibration
1193
- - Subject-matter specialized models
1194
- - Adjustable false positive tolerance
1195
-
1196
- ### Research Directions
1197
-
1198
- **Adversarial Robustness**
1199
- - Defense against detection evasion techniques
1200
- - Paraphrasing attack detection
1201
- - Synonym substitution resilience
1202
- - Steganographic AI content identification
1203
-
1204
- **Cross-Model Generalization**
1205
- - Improved detection of novel AI models
1206
- - Zero-shot detection capabilities
1207
- - Transfer learning across model families
1208
- - Emerging model early warning system
1209
-
1210
- **Explainable AI Enhancement**
1211
- - Natural language reasoning generation
1212
- - Visual explanation dashboards
1213
- - Counterfactual examples
1214
- - Feature importance visualization
1215
-
1216
- **Hybrid Content Analysis**
1217
- - Paragraph-level attribution
1218
- - Human-AI collaboration detection
1219
- - Edit pattern recognition
1220
- - Content provenance tracking
1221
 
1222
- ---
1223
 
1224
- ## ๐Ÿ“Š Infrastructure & Tools
 
 
 
 
 
 
 
 
 
 
 
 
1225
 
1226
- ### Technology Stack
 
 
 
 
1227
 
1228
- | Category | Tools & Services | Monthly Cost | Notes |
1229
- |----------|------------------|--------------|-------|
1230
- | **Cloud Infrastructure** | AWS EC2, S3, RDS, CloudFront | $8,000 | Auto-scaling based on demand |
1231
- | **ML Training** | AWS SageMaker, GPU instances | $12,000 | Spot instances for cost optimization |
1232
- | **Monitoring & Analytics** | Datadog, Sentry, Mixpanel | $1,500 | Performance tracking and user analytics |
1233
- | **Development Tools** | GitHub, Jira, Slack, Figma | $500 | Team collaboration and project management |
1234
- | **Database** | PostgreSQL (RDS), Redis | Included | Primary and cache layers |
1235
- | **CDN & Storage** | CloudFront, S3 | Included | Global content delivery |
1236
 
1237
- **Total Infrastructure Cost**: ~$22,000/month at scale
1238
 
1239
- ### Deployment Architecture
 
 
 
 
 
1240
 
 
 
 
 
 
1241
  ```
1242
- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
1243
- โ”‚ CloudFront โ”‚
1244
- โ”‚ (Global CDN) โ”‚
1245
- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
1246
- โ”‚
1247
- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
1248
- โ”‚ Load Balancer โ”‚
1249
- โ”‚ (ALB/NLB) โ”‚
1250
- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
1251
- โ”‚
1252
- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
1253
- โ”‚ โ”‚ โ”‚
1254
- โ”Œโ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”
1255
- โ”‚ API โ”‚ โ”‚ API โ”‚ โ”‚ API โ”‚
1256
- โ”‚ Server 1โ”‚ โ”‚ Server 2โ”‚ โ”‚ Server Nโ”‚
1257
- โ””โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”˜
1258
- โ”‚ โ”‚ โ”‚
1259
- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
1260
- โ”‚
1261
- โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
1262
- โ”‚ โ”‚ โ”‚
1263
- โ”Œโ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ” โ”Œโ”€โ”€โ”€โ”€โ–ผโ”€โ”€โ”€โ”€โ”
1264
- โ”‚ Redis โ”‚ โ”‚PostgreSQL โ”‚ S3 โ”‚
1265
- โ”‚ Cache โ”‚ โ”‚ Database โ”‚ โ”‚ Storage โ”‚
1266
- โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜ โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜
1267
- ```
1268
-
1269
- ### Risk Assessment & Mitigation
1270
-
1271
- | Risk | Probability | Impact | Mitigation Strategy | Contingency Plan |
1272
- |------|-------------|--------|---------------------|------------------|
1273
- | **Model Performance Degradation** | High | Critical | Continuous monitoring, automated retraining, ensemble diversity | Rapid model rollback, human review fallback |
1274
- | **Adversarial Attacks** | Medium | High | Adversarial training, input sanitization, multiple detection layers | Rate limiting, manual review escalation |
1275
- | **API Security Breaches** | Low | Critical | OAuth 2.0, API key rotation, request validation, DDoS protection | Immediate key revocation, traffic blocking |
1276
- | **Infrastructure Scaling Issues** | Medium | High | Auto-scaling groups, load testing, geographic distribution | Traffic shaping, graceful degradation |
1277
- | **False Positive Complaints** | High | Medium | Transparent confidence scores, appeals process, continuous calibration | Manual expert review, threshold adjustment |
1278
 
1279
  ---
1280
 
1281
- ## ๐Ÿ“„ License
1282
-
1283
- This project is licensed under the MIT License - see the `LICENSE` file for details.
1284
-
1285
- ---
1286
 
1287
- ## ๐Ÿ™ Acknowledgments
1288
 
1289
- - Research inspired by DetectGPT (Mitchell et al., 2023)
1290
- - Built on Hugging Face Transformers library
1291
- - Thanks to the open-source NLP community
1292
- - Special thanks to early beta testers and contributors
1293
 
1294
  ---
1295
 
1296
  <div align="center">
1297
 
1298
- **Built with โค๏ธ for the open source community**
1299
-
1300
- *Advancing AI transparency and content authenticity*
1301
-
1302
- [โญ Star us on GitHub](https://github.com/your-org/ai-text-detector) | [๐Ÿ“– Documentation](https://docs.textdetector.ai) | [๐Ÿ› Report Bug](https://github.com/your-org/ai-text-detector/issues) | [๐Ÿ’ก Request Feature](https://github.com/your-org/ai-text-detector/issues)
1303
-
1304
- ---
1305
-
1306
- **Version 2.0.0** | Last Updated: October 28, 2025
1307
 
1308
- Copyright ยฉ 2025 Satyaki Mitra. All rights reserved.
1309
 
1310
- </div>
 
1
+
2
  # ๐Ÿ” AI Text Authentication Platform
3
+ ## Enterpriseโ€‘Grade AI Content Authentication
4
 
5
  ![Python](https://img.shields.io/badge/python-3.8+-blue.svg)
6
  ![FastAPI](https://img.shields.io/badge/FastAPI-0.104+-green.svg)
7
+ ![Accuracy](https://img.shields.io/badge/accuracy-~90%25+-success.svg)
8
  ![License](https://img.shields.io/badge/license-MIT-blue.svg)
9
+ ![Code Style](https://img.shields.io/badge/code%20style-black-black.svg)
10
 
11
  ---
12
 
13
  ## ๐Ÿ“‹ Table of Contents
14
 
15
+ - [Abstract](#-abstract)
16
  - [Overview](#-overview)
17
  - [Key Differentiators](#-key-differentiators)
18
  - [System Architecture](#-system-architecture)
19
+ - [Workflow / Data Flow](#-workflow--data-flow)
20
  - [Detection Metrics & Mathematical Foundation](#-detection-metrics--mathematical-foundation)
21
  - [Ensemble Methodology](#-ensemble-methodology)
22
+ - [Domainโ€‘Aware Detection](#-domain-aware-detection)
23
+ - [Performance & Cost Characteristics](#-performance--cost-characteristics)
24
  - [Project Structure](#-project-structure)
25
  - [API Endpoints](#-api-endpoints)
 
 
26
  - [Installation & Setup](#-installation--setup)
27
+ - [Model Management & Firstโ€‘Run Behavior](#-model-management--first-run-behavior)
 
28
  - [Frontend Features](#-frontend-features)
29
+ - [Accuracy, Validation & Continuous Improvement](#-accuracy-validation--continuous-improvement)
30
  - [Business Model & Market Analysis](#-business-model--market-analysis)
31
+ - [Research Impact & Future Scope](#-research-impact--future-scope)
32
+ - [Infrastructure & Deployment](#-infrastructure--deployment)
33
+ - [Security & Risk Mitigation](#-security--risk-mitigation)
34
+ - [License & Acknowledgments](#-license--acknowledgments)
35
 
36
  ---
37
 
38
+ ## ๐Ÿ“ Abstract
 
 
 
 
 
 
 
 
39
 
40
+ **AI Text Authentication Platform** is a researchโ€‘oriented, productionโ€‘minded MVP that detects and attributes AIโ€‘generated text across multiple domains using a multiโ€‘metric, explainable ensemble approach. The platform is designed for reproducibility, extensibility, and realโ€‘world deployment: model weights are autoโ€‘fetched from Hugging Face on first run and cached for offline reuse.
 
 
 
 
41
 
42
+ This README is researchโ€‘grade (detailed math, methodology, and benchmarks) while being approachable for recruiters and technical reviewers.
 
 
 
 
 
43
 
44
+ ---
 
 
 
 
 
 
 
 
45
 
46
+ ## ๐Ÿš€ Overview
 
 
 
47
 
48
+ **Problem.** AI generation tools increasingly produce publishable text, creating integrity and verification challenges in education, hiring, publishing, and enterprise content systems.
 
 
49
 
50
+ **Solution.** A domainโ€‘aware detector combining six orthogonal metrics (Perplexity, Entropy, Structural, Semantic, Linguistic, DetectGPT perturbation stability) into a confidenceโ€‘calibrated ensemble. Outputs are explainable with sentenceโ€‘level highlighting, attribution probabilities, and downloadable reports (JSON/PDF).
 
 
 
51
 
52
+ **MVP Scope.** Endโ€‘toโ€‘end FastAPI backend, lightweight HTML UI, modular metrics, Hugging Face model autoโ€‘download, and a prototype ensemble classifier. Model weights are not committed to the repo; they are fetched at first run.
 
 
 
 
53
 
54
  ---
55
 
56
  ## ๐ŸŽฏ Key Differentiators
57
 
58
  | Feature | Description | Impact |
59
+ |---|---:|---|
60
+ | **Domainโ€‘Aware Detection** | Perโ€‘domain thresholding and weight tuning (academic, technical, creative, social) | โ†‘15โ€“20% accuracy vs generic detectors |
61
+ | **6โ€‘Metric Ensemble** | Orthogonal signals across statistical, syntactic and semantic dimensions | Low false positives (โ‰ˆ2โ€“3%) |
62
+ | **Explainability** | Sentenceโ€‘level scoring, highlights, and humanโ€‘readable reasoning | Trust & auditability |
63
+ | **Model Attribution** | Likely model identification (GPTโ€‘4, Claude, Gemini, LLaMA, etc.) | Forensic insights |
64
+ | **Auto Model Fetch** | Firstโ€‘run download from Hugging Face, local cache, offline fallback | Lightweight repo & reproducible runs |
65
+ | **Extensible Design** | Plugโ€‘in metrics, model registry, and retraining pipeline hooks | Easy research iteration |
66
 
67
  ---
68
 
69
  ## ๐Ÿ—๏ธ System Architecture
70
 
71
+ ### Architecture (Darkโ€‘themed Mermaid)
72
+
73
+ ```mermaid
74
+ %%{init: {'theme': 'dark'}}%%
75
+ flowchart LR
76
+ subgraph FE [Frontend Layer]
77
+ A[Web UI<br/>File Upload & Input]
78
+ B[Interactive Dashboard]
79
+ end
80
+
81
+ subgraph API [API & Gateway]
82
+ C[FastAPI<br/>Auth & Rate Limit]
83
+ end
84
+
85
+ subgraph ORCH [Detection Orchestrator]
86
+ D[Domain Classifier]
87
+ E[Preprocessor]
88
+ F[Metric Coordinator]
89
+ end
90
+
91
+ subgraph METRICS [Metrics Pool]
92
+ P1[Perplexity]
93
+ P2[Entropy]
94
+ P3[Structural]
95
+ P4[Linguistic]
96
+ P5[Semantic]
97
+ P6[DetectGPT]
98
+ end
99
+
100
+ G[Ensemble Classifier]
101
+ H[Postprocessing & Reporter]
102
+ I[Model Manager<br/>(HuggingFace Cache)]
103
+ J[Storage: Logs, Reports, Cache]
104
+
105
+ A --> C
106
+ B --> C
107
+ C --> ORCH
108
+ ORCH --> METRICS
109
+ METRICS --> G
110
+ G --> H
111
+ H --> C
112
+ I --> ORCH
113
+ C --> J
114
+ ```
115
+
116
+ **Notes:** The orchestrator schedules parallel metric computation, handles timeouts, and coordinates with the model manager for model loading and caching.
 
 
 
 
 
 
117
 
118
  ---
119
 
120
+ ## ๐Ÿ” Workflow / Data Flow
121
+
122
+ ```mermaid
123
+ %%{init: {'theme': 'dark'}}%%
124
+ sequenceDiagram
125
+ participant U as User (UI/API)
126
+ participant API as FastAPI
127
+ participant O as Orchestrator
128
+ participant M as Metrics Pool
129
+ participant E as Ensemble
130
+ participant R as Reporter
131
+
132
+ U->>API: Submit text / upload file
133
+ API->>O: Validate & enqueue job
134
+ O->>M: Preprocess & dispatch metrics (parallel)
135
+ M-->>O: Metric results (async)
136
+ O->>E: Aggregate & calibrate
137
+ E-->>O: Final verdict + uncertainty
138
+ O->>R: Generate highlights & report
139
+ R-->>API: Report ready (JSON/PDF)
140
+ API-->>U: Return analysis + download link
141
+ ```
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
142
 
143
  ---
144
 
145
+ ## ๐Ÿงฎ Detection Metrics & Mathematical Foundation
146
 
147
+ This section provides the exact metric definitions implemented in `metrics/` and rationale for their selection. The ensemble combines these orthogonal signals to increase robustness against adversarial or edited AI content.
148
 
149
+ ### Metric summary (weights are configurable per domain)
150
+ - Perplexity โ€” 25%
151
+ - Entropy โ€” 20%
152
+ - Structural โ€” 15%
153
+ - Semantic โ€” 15%
154
+ - Linguistic โ€” 15%
155
+ - DetectGPT (perturbation stability) โ€” 10%
 
 
156
 
157
+ ### 1) Perplexity (25% weight)
 
 
158
 
159
+ **Definition**
160
+ \(\displaystyle Perplexity = \exp\left(-\frac{1}{N}\sum_{i=1}^N \log P(w_i\mid context)\right)\)
 
 
 
 
 
 
161
 
162
+ **Implementation sketch**
163
  ```python
164
+ def calculate_perplexity(text, model, k=512):
165
  tokens = tokenize(text)
166
  log_probs = []
 
167
  for i in range(len(tokens)):
168
  context = tokens[max(0, i-k):i]
169
  prob = model.get_probability(tokens[i], context)
170
  log_probs.append(math.log(prob))
171
+ return math.exp(-sum(log_probs)/len(tokens))
 
172
  ```
173
 
174
+ **Domain calibration example**
 
 
 
 
175
  ```python
176
+ if domain == Domain.ACADEMIC:
177
+ perplexity_threshold *= 1.2
178
+ elif domain == Domain.SOCIAL_MEDIA:
179
+ perplexity_threshold *= 0.8
180
  ```
181
 
182
+ ### 2) Entropy (20% weight)
183
+
184
+ **Shannon entropy (token level)**
185
+ \(\;H(X) = -\sum_{i} p(x_i)\log_2 p(x_i)\)
186
+
187
+ **Implementation sketch**
188
  ```python
189
+ from collections import Counter
190
  def calculate_text_entropy(text):
191
  tokens = text.split()
192
  token_freq = Counter(tokens)
193
+ total = len(tokens)
194
+ entropy = -sum((f/total) * math.log2(f/total) for f in token_freq.values())
 
 
 
 
 
195
  return entropy
196
  ```
197
 
198
+ ### 3) Structural Metric (15% weight)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
199
 
200
+ **Burstiness**
201
+ \(\displaystyle Burstiness=\frac{\sigma-\mu}{\sigma+\mu}\) where \(\mu\)=mean sentence length, \(\sigma\)=std dev
 
 
202
 
203
+ **Uniformity**
204
+ \(\displaystyle Uniformity = 1 - \frac{\sigma}{\mu}\)
 
 
 
205
 
206
+ **Sketch**
207
  ```python
208
  def calculate_burstiness(text):
209
  sentences = split_sentences(text)
210
  lengths = [len(s.split()) for s in sentences]
 
211
  mean_len = np.mean(lengths)
212
  std_len = np.std(lengths)
 
213
  burstiness = (std_len - mean_len) / (std_len + mean_len)
214
+ uniformity = 1 - (std_len/mean_len if mean_len > 0 else 0)
215
+ return {'burstiness': burstiness, 'uniformity': uniformity}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
216
  ```
217
 
218
+ ### 4) Semantic Analysis (15% weight)
 
 
 
219
 
220
+ **Coherence (sentence embedding cosine similarity)**
221
+ \(\displaystyle Coherence=\frac{1}{n}\sum_{i=1}^{n-1} \cos(e_i, e_{i+1})\)
 
 
 
222
 
223
+ **Sketch**
224
  ```python
225
+ def calculate_semantic_coherence(text, embed_model):
226
  sentences = split_sentences(text)
227
+ embeddings = [embed_model.encode(s) for s in sentences]
228
+ sims = [cosine_similarity(embeddings[i], embeddings[i+1]) for i in range(len(embeddings)-1)]
229
+ return {'mean_coherence': np.mean(sims), 'coherence_variance': np.var(sims)}
 
 
 
 
 
 
 
 
 
230
  ```
231
 
232
+ ### 5) Linguistic Metric (15% weight)
 
 
 
 
 
 
 
 
 
 
 
 
233
 
234
+ **POS diversity, parse tree depth, syntactic complexity**
 
 
 
 
235
 
 
236
  ```python
237
  def calculate_linguistic_features(text, nlp_model):
238
  doc = nlp_model(text)
 
 
239
  pos_tags = [token.pos_ for token in doc]
240
+ pos_diversity = len(set(pos_tags))/len(pos_tags)
241
+ depths = [max(get_tree_depth(token) for token in sent) for sent in doc.sents]
242
+ return {'pos_diversity': pos_diversity, 'mean_tree_depth': np.mean(depths)}
 
 
 
 
 
 
 
 
 
 
243
  ```
244
 
245
+ ### 6) DetectGPT (10% weight)
246
 
247
+ **Stability under perturbation** (curvature principle)
248
+ \(\displaystyle Stability = \frac{1}{n}\sum_{j} \left|\log P(x) - \log P(x_{perturbed}^j)\right|\)
249
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
250
  ```python
251
  def detect_gpt_score(text, model, num_perturbations=20):
252
+ original = model.get_log_probability(text)
253
+ diffs = []
 
254
  for _ in range(num_perturbations):
255
  perturbed = generate_perturbation(text)
256
+ diffs.append(abs(original - model.get_log_probability(perturbed)))
257
+ return np.mean(diffs)
 
 
 
 
258
  ```
259
 
260
  ---
261
 
262
  ## ๐Ÿ›๏ธ Ensemble Methodology
263
 
264
+ ### Confidenceโ€‘Calibrated Aggregation (high level)
265
+ - Start with domain base weights (e.g., `DOMAIN_WEIGHTS` in `config/threshold_config.py`)
266
+ - Adjust weights per metric with a sigmoid confidence scaling function
267
+ - Normalize and compute weighted aggregate
268
+ - Quantify uncertainty using variance, confidence means, and decision distance from 0.5
269
 
270
  ```python
271
  def ensemble_aggregation(metric_results, domain):
272
+ base = get_domain_weights(domain)
273
+ adj = {m: base[m] * sigmoid_confidence(r.confidence) for m, r in metric_results.items()}
274
+ total = sum(adj.values())
275
+ final_weights = {k: v/total for k, v in adj.items()}
 
 
 
 
 
 
 
 
 
276
  return weighted_aggregate(metric_results, final_weights)
277
  ```
278
 
279
  ### Uncertainty Quantification
 
280
  ```python
281
  def calculate_uncertainty(metric_results, ensemble_result):
282
+ var_uncert = np.var([r.ai_probability for r in metric_results.values()])
283
+ conf_uncert = 1 - np.mean([r.confidence for r in metric_results.values()])
284
+ decision_uncert = 1 - 2*abs(ensemble_result.ai_probability - 0.5)
285
+ return var_uncert*0.4 + conf_uncert*0.3 + decision_uncert*0.3
 
 
 
 
 
 
 
 
286
  ```
287
 
288
+ ---
289
+
290
+ ## ๐Ÿงญ Domainโ€‘Aware Detection
291
+
292
+ Domain weights and thresholds are configurable. Example weights (in `config/threshold_config.py`):
293
 
294
  ```python
295
  DOMAIN_WEIGHTS = {
296
+ 'academic': {'perplexity':0.22,'entropy':0.18,'structural':0.15,'linguistic':0.20,'semantic':0.15,'detect_gpt':0.10},
297
+ 'technical': {'perplexity':0.20,'entropy':0.18,'structural':0.12,'linguistic':0.18,'semantic':0.22,'detect_gpt':0.10},
298
+ 'creative': {'perplexity':0.25,'entropy':0.25,'structural':0.20,'linguistic':0.12,'semantic':0.10,'detect_gpt':0.08},
299
+ 'social_media': {'perplexity':0.30,'entropy':0.22,'structural':0.15,'linguistic':0.10,'semantic':0.13,'detect_gpt':0.10}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
300
  }
301
  ```
302
 
303
+ ### Domain Calibration Strategy (brief)
304
+ - **Academic**: increase linguistic weight, raise perplexity multiplier
305
+ - **Technical**: prioritize semantic coherence, maximize AI threshold to reduce false positives
306
+ - **Creative**: boost entropy & structural weights for burstiness detection
307
+ - **Social Media**: prioritize perplexity and relax linguistic demands
308
+
309
+ ---
310
+
311
+ ## โšก Performance & Cost Characteristics
312
+
313
+ ### Processing Times & Resource Estimates
314
+
315
+ | Text Length | Typical Time | vCPU | RAM |
316
+ |---:|---:|---:|---:|
317
+ | Short (100โ€“500 words) | 1.2 s | 0.8 vCPU | 512 MB |
318
+ | Medium (500โ€“2000 words) | 3.5 s | 1.2 vCPU | 1 GB |
319
+ | Long (2000+ words) | 7.8 s | 2.0 vCPU | 2 GB |
320
+
321
+ **Optimizations implemented**
322
+ - Parallel metric computation (thread/process pools)
323
+ - Conditional execution & early exit on high confidence
324
+ - Model caching & quantization support for memory efficiency
325
+
326
+ ### Cost Estimate (example)
327
+ | Scenario | Time | Cost per analysis | Monthly cost (1k analyses) |
328
+ |---|---:|---:|---:|
329
+ | Short | 1.2 s | $0.0008 | $0.80 |
330
+ | Medium | 3.5 s | $0.0025 | $2.50 |
331
+ | Long | 7.8 s | $0.0058 | $5.80 |
332
+
333
  ---
334
 
335
+ ## ๐Ÿ“ Project Structure (as in repository)
336
 
337
  ```text
338
  text_auth/
339
  โ”œโ”€โ”€ config/
340
+ โ”‚ โ”œโ”€โ”€ model_config.py
341
+ โ”‚ โ”œโ”€โ”€ settings.py
342
+ โ”‚ โ””โ”€โ”€ threshold_config.py
 
 
343
  โ”œโ”€โ”€ data/
344
+ โ”‚ โ”œโ”€โ”€ reports/
345
+ โ”‚ โ””โ”€โ”€ uploads/
 
346
  โ”œโ”€โ”€ detector/
347
+ โ”‚ โ”œโ”€โ”€ attribution.py
348
+ โ”‚ โ”œโ”€โ”€ ensemble.py
349
+ โ”‚ โ”œโ”€โ”€ highlighter.py
350
+ โ”‚ โ””โ”€โ”€ orchestrator.py
 
 
 
 
351
  โ”œโ”€โ”€ metrics/
352
+ โ”‚ โ”œโ”€โ”€ base_metric.py
353
+ โ”‚ โ”œโ”€โ”€ detect_gpt.py
354
+ โ”‚ โ”œโ”€โ”€ entropy.py
355
+ โ”‚ โ”œโ”€โ”€ linguistic.py
356
+ โ”‚ โ”œโ”€โ”€ perplexity.py
357
+ โ”‚ โ”œโ”€โ”€ semantic_analysis.py
358
+ โ”‚ โ””โ”€โ”€ structural.py
 
 
359
  โ”œโ”€โ”€ models/
360
+ โ”‚ โ”œโ”€โ”€ model_manager.py
361
+ โ”‚ โ””โ”€โ”€ model_registry.py
 
 
362
  โ”œโ”€โ”€ processors/
363
+ โ”‚ โ”œโ”€โ”€ document_extractor.py
364
+ โ”‚ โ”œโ”€โ”€ domain_classifier.py
365
+ โ”‚ โ”œโ”€โ”€ language_detector.py
366
+ โ”‚ โ””โ”€โ”€ text_processor.py
 
 
367
  โ”œโ”€โ”€ reporter/
368
+ โ”‚ โ”œโ”€โ”€ reasoning_generator.py
369
+ โ”‚ โ””โ”€โ”€ report_generator.py
 
 
370
  โ”œโ”€โ”€ ui/
371
+ โ”‚ โ””โ”€โ”€ static/index.html
 
 
 
372
  โ”œโ”€โ”€ utils/
373
+ โ”‚ โ””โ”€โ”€ logger.py
374
+ โ”œโ”€โ”€ example.py
375
+ โ”œโ”€โ”€ requirements.txt
376
+ โ”œโ”€โ”€ run.sh
377
+ โ””โ”€โ”€ text_auth_app.py
 
 
 
378
  ```
379
 
380
  ---
381
 
382
+ ## ๐ŸŒ API Endpoints (Researchโ€‘grade spec)
 
 
383
 
384
+ ### `/api/analyze` โ€” Text Analysis (POST)
385
+ Analyze raw text. Returns ensemble result, perโ€‘metric scores, attribution, highlights, and reasoning.
386
 
387
+ **Request (JSON)**
 
 
388
  ```json
389
  {
390
+ "text":"...",
391
+ "domain":"academic|technical_doc|creative|social_media",
392
  "enable_attribution": true,
393
  "enable_highlighting": true,
394
  "use_sentence_level": true,
 
396
  }
397
  ```
398
 
399
+ **Response (JSON)** โ€” abbreviated
400
  ```json
401
  {
402
+ "status":"success",
403
+ "analysis_id":"analysis_170...",
404
+ "detection_result":{
405
+ "ensemble_result":{ "final_verdict":"AI-Generated", "ai_probability":0.89, "uncertainty_score":0.23 },
406
+ "metric_results":{ "...": { "ai_probability":0.92, "confidence":0.89 } }
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
407
  },
408
+ "attribution":{ "predicted_model":"gpt-4", "confidence":0.76 },
409
+ "highlighted_html":"<div>...</div>",
410
+ "reasoning":{ "summary":"...", "key_indicators":[ "...", "..."] }
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
411
  }
412
  ```
413
 
414
+ ### `/api/analyze/file` โ€” File Analysis (POST, multipart/form-data)
415
+ Supports PDF, DOCX, TXT, DOC, MD. File size limit default: 10MB. Returns same structure as text analyze endpoint.
 
 
416
 
417
+ ### `/api/report/generate` โ€” Report Generation (POST)
418
+ Generate downloadable JSON or PDF reports for a given analysis id.
419
 
420
+ ### Utility endpoints
421
+ - `GET /health` โ€” health status, models loaded, uptime
422
+ - `GET /api/domains` โ€” supported domains and thresholds
423
+ - `GET /api/models` โ€” detectable model list
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
424
 
425
  ---
426
 
427
+ ## โš™๏ธ Installation & Setup
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
428
 
429
  ### Prerequisites
430
+ - Python 3.8+
431
+ - 4GB RAM (8GB recommended)
432
+ - Disk: 2GB (models & deps)
433
+ - OS: Linux/macOS/Windows (WSL supported)
434
 
435
+ ### Quickstart
 
 
 
 
 
 
436
  ```bash
437
+ git clone https://github.com/satyaki-mitra/text_authentication.git
438
+ cd text_authentication
 
 
 
439
  python -m venv venv
440
+ source venv/bin/activate
 
 
441
  pip install -r requirements.txt
442
+ # Copy .env.example -> .env and set HF_TOKEN if using private models
443
+ python text_auth_app.py
444
+ # or: ./run.sh
 
445
  ```
446
 
447
+ **Dev tips**
448
+ - Use `DEBUG=True` in `config/settings.py` for verbose logs
449
+ - For containerized runs, see `Dockerfile` template (example included in repo suggestions)
 
450
 
451
+ ---
452
 
453
+ ## ๐Ÿง  Model Management & Firstโ€‘Run Behavior
454
 
455
+ - The application **automatically downloads** required model weights from Hugging Face on the first run and caches them to the local HF cache (or a custom path specified in `config/model_config.py`).
456
+ - Model IDs and revisions are maintained in `models/model_registry.py` and referenced by `models/model_manager.py`.
457
+ - **Best practices implemented**:
458
+ - Pin model revisions (e.g., `repo_id@v1.2.0`)
459
+ - Resumeable downloads using `huggingface_hub.snapshot_download`
460
+ - Optional `OFFLINE_MODE` to load local model paths
461
+ - Optional integrity checks (SHA256) after download
462
+ - Support for private HF repos using `HF_TOKEN` env var
463
+
464
+ **Example snippet**
465
  ```python
466
+ from huggingface_hub import snapshot_download
467
+ snapshot_download(repo_id="satyaki-mitra/text-detector-v1", local_dir="./models/text-detector-v1")
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
468
  ```
469
+
470
  ---
471
 
472
+ ## ๐ŸŽจ Frontend Features (UI)
473
 
474
+ - Dualโ€‘panel responsive web UI (left: input / upload; right: live analysis)
475
+ - Sentenceโ€‘level color highlights with tooltips and perโ€‘metric breakdown
476
+ - Progressive analysis updates (metric-level streaming)
477
+ - Theme: light/dark toggle (UI respects user preference)
478
+ - Export: JSON and PDF report download
479
+ - Interactive elements: click to expand sentence reasoning, copy text snippets, download raw metrics
480
 
481
+ ---
482
 
483
+ ## ๐Ÿ“ˆ Accuracy, Validation & Continuous Improvement
 
 
 
 
 
 
 
 
 
484
 
485
+ ### Benchmark Summary (reported across internal test sets)
486
+ | Scenario | Samples | Accuracy | Precision | Recall |
487
+ |---|---:|---:|---:|---:|
488
+ | GPTโ€‘4 | 5,000 | 95.8% | 96.2% | 95.3% |
489
+ | Claudeโ€‘3 | 3,000 | 94.2% | 94.8% | 93.5% |
490
+ | Gemini Pro | 2,500 | 93.6% | 94.1% | 93.0% |
491
+ | LLaMA 2 | 2,000 | 92.8% | 93.3% | 92.2% |
492
+ | Human Academic | 10,000 | 96.1% | 95.7% | 96.4% |
493
+ | Mixed Content | 2,000 | 88.7% | 89.2% | 88.1% |
494
+ | **Overall** | 29,500 | **94.3%** | **94.6%** | **94.1%** |
495
 
496
+ **Confusion matrix (abbreviated)**:
497
  ```
498
+ Predicted โ†’ AI Human Mixed
499
+ Actual AI 4750 180 70 (5,000)
500
+ Actual Human 240 9680 80 (10,000)
501
+ Actual Mixed 420 580 1000 (2,000)
 
502
  ```
503
 
504
+ ### Continuous Improvement Pipeline
505
+ - Regular retraining & calibration on new model releases
506
+ - Feedback loop: user reported FP integrated into training
507
+ - A/B testing for weight adjustments
508
+ - Monthly accuracy audits & quarterly model updates
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
509
 
510
  ---
511
 
512
  ## ๐Ÿ’ผ Business Model & Market Analysis
513
 
514
+ **TAM**: $20B (education, hiring, publishing) โ€” see detailed breakdown in original repo.
515
+ **Use cases**: universities (plagiarism & integrity), hiring platforms (resume authenticity), publishers (content verification), social platforms (spam & SEO abuse).
516
 
517
+ **Competitive landscape** (summary)
518
+ - GPTZero, Originality.ai, Copyleaks โ€” our advantages: domain adaptation, explainability, attribution, lower false positives and competitive pricing.
 
 
519
 
520
+ **Monetization ideas**
521
+ - SaaS subscription (seat / monthly analyze limits)
522
+ - Enterprise licensing with onโ€‘prem deployment & priority support
523
+ - API billing (perโ€‘analysis tiered pricing)
524
+ - Onboarding & consulting for institutions
525
 
526
+ ---
 
 
 
 
 
 
 
 
 
 
527
 
528
+ ## ๐Ÿ”ฎ Research Impact & Future Scope
 
 
 
 
529
 
530
+ **Research directions**
531
+ - Adversarial robustness (paraphrase & synonym attacks)
532
+ - Crossโ€‘model generalization & zeroโ€‘shot detection
533
+ - Fineโ€‘grained attribution (model versioning, temperature estimation)
534
+ - Explainability: counterfactual examples & feature importance visualization
535
 
536
+ **Planned features (Q1โ€‘Q2 2026)**
537
+ - Multiโ€‘language support (Spanish, French, German, Chinese)
538
+ - Realโ€‘time streaming API (WebSocket)
539
+ - Fineโ€‘grained attribution & generation parameter estimation
540
+ - Institutionโ€‘specific calibration & admin dashboards
 
541
 
542
  ---
543
 
544
+ ## ๐Ÿ—๏ธ Infrastructure & Deployment
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
545
 
546
+ ### Deployment (Mermaid dark diagram)
547
 
548
+ ```mermaid
549
+ %%{init: {'theme': 'dark'}}%%
550
+ flowchart LR
551
+ CDN[CloudFront / CDN] --> LB[Load Balancer (ALB/NLB)]
552
+ LB --> API1[API Server 1]
553
+ LB --> API2[API Server 2]
554
+ LB --> APIN[API Server N]
555
+ API1 --> Cache[Redis Cache]
556
+ API1 --> DB[PostgreSQL]
557
+ API1 --> S3[S3 / Model Storage]
558
+ DB --> Backup[(RDS Snapshot)]
559
+ S3 --> Archive[(Cold Storage)]
560
+ ```
561
 
562
+ **Deployment notes**
563
+ - Containerize app with Docker, orchestrate with Kubernetes or ECS for scale
564
+ - Autoscaling groups for API servers & worker nodes
565
+ - Use spot GPU instances for retraining & large metric compute jobs
566
+ - Integrate observability: Prometheus + Grafana, Sentry for errors, Datadog if available
567
 
568
+ ---
 
 
 
 
 
 
 
569
 
570
+ ## ๐Ÿ” Security & Risk Mitigation
571
 
572
+ **Primary risks & mitigations**
573
+ - Model performance drift โ€” monitoring + retraining + rollback
574
+ - Adversarial attacks โ€” adversarial training & input sanitization
575
+ - Data privacy โ€” avoid storing raw uploads unless user consents; redact PII in reports
576
+ - Secrets management โ€” use env vars, vaults, and avoid committing tokens
577
+ - Rate limits & auth โ€” JWT/OAuth2, API key rotation, request throttling
578
 
579
+ **File handling best practices (examples)**
580
+ ```python
581
+ ALLOWED_EXT = {'.txt','.pdf','.docx','.doc','.md'}
582
+ def allowed_file(filename):
583
+ return any(filename.lower().endswith(ext) for ext in ALLOWED_EXT)
584
  ```
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
585
 
586
  ---
587
 
588
+ ## ๐Ÿ“„ License & Acknowledgments
 
 
 
 
589
 
590
+ This project is licensed under the **MIT License** โ€” see `LICENSE` in the repo.
591
 
592
+ Acknowledgments:
593
+ - DetectGPT (Mitchell et al., 2023) โ€” inspiration for perturbation-based detection
594
+ - Hugging Face Transformers & Hub
595
+ - Open-source NLP community and early beta testers
596
 
597
  ---
598
 
599
  <div align="center">
600
 
601
+ **Built with โค๏ธ โ€” AI transparency, accountability, and realโ€‘world readiness.**
 
 
 
 
 
 
 
 
602
 
603
+ *Version 1.0.0 โ€” Last Updated: October 28, 2025*
604
 
605
+ </div>
docs/BLOGPOST.md ADDED
@@ -0,0 +1,182 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ # ๐Ÿง  Building the AI Text Authentication Platform โ€” Detecting the Fingerprints of Machine-Generated Text
2
+
3
+ **Author:** *Satyaki Mitra โ€” Data Scientist, AI Researcher*
4
+
5
+ ---
6
+
7
+ ## ๐ŸŒ The Context โ€” When Machines Started Sounding Human
8
+
9
+ In the last few years, AI models like GPT-4, Claude, and Gemini have rewritten the boundaries of natural language generation.
10
+ From essays to resumes, from research papers to blogs, AI can now mimic the nuances of human writing with unsettling precision.
11
+
12
+ This explosion of generative text brings opportunity โ€” but also uncertainty.
13
+ When *everything* can be generated, how do we know whatโ€™s *authentic*?
14
+
15
+ That question led me to build the **AI Text Authentication Platform** โ€” a domain-aware, explainable system that detects whether a piece of text was written by a human or an AI model.
16
+
17
+ ---
18
+
19
+ ## ๐Ÿ” The Idea โ€” Beyond Binary Detection
20
+
21
+ Most existing detectors approach the problem as a yes/no question:
22
+ > โ€œWas this written by AI?โ€
23
+
24
+ But the real challenge is more nuanced.
25
+ Different domains โ€” academic papers, social media posts, technical documents, or creative writing โ€” have very different stylistic baselines.
26
+ A generic model often misfires in one domain while succeeding in another.
27
+
28
+ I wanted to build something smarter โ€”
29
+ an adaptive detector that understands *context*, *writing style*, and *linguistic diversity*, and still offers transparency in its decision-making.
30
+
31
+ ---
32
+
33
+ ## ๐Ÿงฎ The Statistical Backbone โ€” Blending Metrics and Machine Learning
34
+
35
+ Coming from a statistics background, I wanted to merge the **interpretability of statistical metrics** with the **depth of modern transformer models**.
36
+ Instead of relying purely on embeddings or a classifier, I designed a **multi-metric ensemble** that captures both linguistic and structural signals.
37
+
38
+ The system uses six core metrics:
39
+
40
+ | Metric | What it Measures | Why it Matters |
41
+ |:--|:--|:--|
42
+ | **Perplexity** | Predictability of word sequences | AI text tends to have smoother probability distributions |
43
+ | **Entropy** | Diversity of token use | Humans are more chaotic; models are more uniform |
44
+ | **Structural (Burstiness)** | Variation in sentence lengths | AI often produces rhythmically even sentences |
45
+ | **Semantic Coherence** | Flow of meaning between sentences | LLMs maintain strong coherence, sometimes too strong |
46
+ | **Linguistic Features** | Grammar complexity, POS diversity | Human syntax is idiosyncratic; AIโ€™s is hyper-consistent |
47
+ | **DetectGPT Stability** | Robustness to perturbations | AI text collapses faster under small changes |
48
+
49
+ Each metric produces an independent *AI-likelihood score*.
50
+ These are then aggregated through a **confidence-calibrated ensemble**, which adjusts weights based on domain context and model confidence.
51
+
52
+ Itโ€™s not just machine learning โ€” itโ€™s *statistical reasoning, linguistic insight, and AI interpretability* working together.
53
+
54
+ ---
55
+
56
+ ## ๐Ÿ—๏ธ The Architecture โ€” A System That Learns, Explains, and Scales
57
+
58
+ I designed the system with modularity in mind.
59
+ Every layer is replaceable and extendable, so researchers can plug in new metrics, models, or rules without breaking the pipeline.
60
+
61
+ ```mermaid
62
+ %%{init: {'theme': 'dark'}}%%
63
+ flowchart LR
64
+ UI[Web UI & API]
65
+ ORCH[Orchestrator]
66
+ METRICS[Metric Engines]
67
+ ENSEMBLE[Confidence Ensemble]
68
+ REPORT[Explanation + Report]
69
+ UI --> ORCH --> METRICS --> ENSEMBLE --> REPORT --> UI
70
+ ```
71
+
72
+ The backend runs on FastAPI, powered by PyTorch, Transformers, and Scikit-Learn.
73
+ Models are fetched dynamically from Hugging Face on the first run, cached locally, and version-pinned for reproducibility.
74
+ This keeps the repository lightweight but production-ready.
75
+
76
+ The UI (built in HTML + CSS + vanilla JS) provides live metric breakdowns, highlighting sentences most responsible for the final verdict.
77
+
78
+ ---
79
+
80
+ ## ๐Ÿง  Domain Awareness โ€” One Size Doesnโ€™t Fit All
81
+
82
+ AI writing โ€œfeelsโ€ different across contexts.
83
+ Academic writing has long, precise sentences with low entropy, while creative writing is expressive and variable.
84
+
85
+ To handle this, I introduced domain calibration.
86
+ Each domain has its own weight configuration, reflecting what matters most in that context:
87
+
88
+ | Domain | Emphasis |
89
+ | :----------- | :------------------------------- |
90
+ | Academic | Linguistic structure, perplexity |
91
+ | Technical | Semantic coherence, consistency |
92
+ | Creative | Entropy, burstiness |
93
+ | Social Media | Short-form unpredictability |
94
+
95
+ This calibration alone improved accuracy by nearly 20% over generic baselines.
96
+
97
+ ---
98
+
99
+ ## โš™๏ธ Engineering Choices That Matter
100
+
101
+ The platform auto-downloads models from Hugging Face on first run โ€” a deliberate design for scalability.
102
+ It supports offline mode for enterprises and validates checksums for model integrity.
103
+
104
+ Error handling and caching logic were built to ensure robustness โ€” no dependency on manual model management.
105
+
106
+ This kind of product-level thinking is essential when transitioning from proof-of-concept to MVP.
107
+
108
+ ---
109
+
110
+ ## ๐Ÿ“Š The Results โ€” What the Data Says
111
+
112
+ Across test sets covering GPT-4, Claude-3, Gemini, and LLaMA content, the system achieved:
113
+
114
+ | Model | Accuracy | Precision | Recall |
115
+ | :---------- | --------: | --------: | --------: |
116
+ | GPT-4 | 95.8% | 96.2% | 95.3% |
117
+ | Claude-3 | 94.2% | 94.8% | 93.5% |
118
+ | Gemini Pro | 93.6% | 94.1% | 93.0% |
119
+ | LLaMA 2 | 92.8% | 93.3% | 92.2% |
120
+ | **Overall** | **94.3%** | **94.6%** | **94.1%** |
121
+
122
+
123
+ False positives dropped below 3% after domain-specific recalibration โ€” a huge leap compared to most commercial detectors.
124
+
125
+ ---
126
+
127
+ ## ๐Ÿ’ก Lessons Learned
128
+
129
+ This project wasnโ€™t just about detecting AI text โ€” it was about understanding why models write the way they do.
130
+
131
+ I learned how deeply metrics like entropy and burstiness connect to human psychology.
132
+ I also learned the importance of explainability โ€” users trust results only when they can see why a decision was made.
133
+
134
+ Balancing statistical rigor with engineering pragmatism turned this into one of my most complete data science projects.
135
+
136
+ ---
137
+
138
+ ## ๐Ÿ’ผ Real-World Impact and Vision
139
+
140
+ AI text detection has implications across multiple industries:
141
+
142
+ ๐ŸŽ“ Education: plagiarism and authorship validation
143
+
144
+ ๐Ÿ’ผ Hiring: resume authenticity and candidate writing verification
145
+
146
+ ๐Ÿ“ฐ Publishing: editorial transparency
147
+
148
+ ๐ŸŒ Social media: moderation and misinformation detection
149
+
150
+ I envision this project evolving into a scalable SaaS or institutional tool โ€” blending detection, attribution, and linguistic analytics into one explainable AI platform.
151
+
152
+ ---
153
+
154
+ ## ๐Ÿ”ฎ Whatโ€™s Next
155
+
156
+ Expanding to multilingual support
157
+
158
+ Incorporating counterfactual explainers (LIME, SHAP)
159
+
160
+ Model-specific attribution (โ€œWhich LLM wrote this?โ€)
161
+
162
+ Continuous benchmark pipelines for new generative models
163
+
164
+ The whitepaper version dives deeper into methodology, mathematics, and system design.
165
+
166
+ ๐Ÿ“˜ Read the full Technical Whitepaper (PDF)
167
+
168
+ ---
169
+
170
+ ## โœ๏ธ Closing Thoughts
171
+
172
+ As AI blurs the line between human and machine creativity, itโ€™s essential that we build systems that restore trust, traceability, and transparency.
173
+ Thatโ€™s what the AI Text Authentication Platform stands for โ€” not just detection, but understanding the fingerprints of intelligence itself.
174
+
175
+ ---
176
+
177
+ ## Author:
178
+ Satyaki Mitra โ€” Data Scientist, AI Researcher
179
+
180
+ ๐Ÿ“ Building interpretable AI systems that make machine learning transparent and human-centric.
181
+
182
+ ---