defense 2025

DAMASHA: Detecting AI in Mixed Adversarial Texts via Segmentation with Human-interpretable Attribution

L. D. M. S. Sai Teja 1, N. Siva Gopala Krishna 2, Ufaq Khan 3, Muhammad Haris Khan 3, Atul Mishra 2

0 citations · 45 references · arXiv

α

Published on arXiv

2512.04838

Output Integrity Attack

OWASP ML Top 10 — ML09

Input Manipulation Attack

OWASP ML Top 10 — ML01

Key Finding

Info-Mask significantly improves span-level robustness under adversarial conditions across multiple architectures, establishing new baselines for mixed human-AI authorship detection under adversarial perturbation

Info-Mask

Novel technique introduced


In the age of advanced large language models (LLMs), the boundaries between human and AI-generated text are becoming increasingly blurred. We address the challenge of segmenting mixed-authorship text, that is identifying transition points in text where authorship shifts from human to AI or vice-versa, a problem with critical implications for authenticity, trust, and human oversight. We introduce a novel framework, called Info-Mask for mixed authorship detection that integrates stylometric cues, perplexity-driven signals, and structured boundary modeling to accurately segment collaborative human-AI content. To evaluate the robustness of our system against adversarial perturbations, we construct and release an adversarial benchmark dataset Mixed-text Adversarial setting for Segmentation (MAS), designed to probe the limits of existing detectors. Beyond segmentation accuracy, we introduce Human-Interpretable Attribution (HIA overlays that highlight how stylometric features inform boundary predictions, and we conduct a small-scale human study assessing their usefulness. Across multiple architectures, Info-Mask significantly improves span-level robustness under adversarial conditions, establishing new baselines while revealing remaining challenges. Our findings highlight both the promise and limitations of adversarially robust, interpretable mixed-authorship detection, with implications for trust and oversight in human-AI co-authorship.


Key Contributions

  • Info-Mask framework integrating stylometric cues, perplexity-driven signals, and structured boundary modeling for adversarially robust mixed-authorship text segmentation
  • MAS adversarial benchmark dataset for evaluating AI text detector robustness against NLP-level evasion attacks (word/character substitution, paraphrasing)
  • Human-Interpretable Attribution (HIA) overlays that surface stylometric features driving boundary predictions, validated in a human study

🛡️ Threat Analysis

Input Manipulation Attack

Constructs the MAS adversarial benchmark using text-level evasion attacks (word substitution, paraphrasing via BAE, HotFlip, etc.) targeting the AI content detector at inference time, and Info-Mask explicitly defends against these adversarial perturbations.

Output Integrity Attack

Primary contribution is a novel framework (Info-Mask) for detecting AI-generated content in mixed-authorship text, directly targeting output integrity and AI content authenticity/provenance.


Details

Domains
nlp
Model Types
llmtransformer
Threat Tags
inference_timedigitalblack_box
Datasets
MASCoAuthorMixSetRoFT-chatgpt
Applications
ai-generated text detectionmixed authorship segmentationacademic integritycontent authenticity