The Erosion of LLM Signatures: Can We Still Distinguish Human and LLM-Generated Scientific Ideas After Iterative Paraphrasing?
Sadat Shahriar , Navid Ayoobi , Arjun Mukherjee
Published on arXiv
2512.05311
Output Integrity Attack
OWASP ML Top 10 — ML09
Key Finding
Detection performance declines by an average of 25.4% after five consecutive paraphrasing stages, with paraphrasing into simplified non-expert style contributing most to the erosion of distinguishable LLM signatures.
With the increasing reliance on LLMs as research agents, distinguishing between LLM and human-generated ideas has become crucial for understanding the cognitive nuances of LLMs' research capabilities. While detecting LLM-generated text has been extensively studied, distinguishing human vs LLM-generated scientific idea remains an unexplored area. In this work, we systematically evaluate the ability of state-of-the-art (SOTA) machine learning models to differentiate between human and LLM-generated ideas, particularly after successive paraphrasing stages. Our findings highlight the challenges SOTA models face in source attribution, with detection performance declining by an average of 25.4\% after five consecutive paraphrasing stages. Additionally, we demonstrate that incorporating the research problem as contextual information improves detection performance by up to 2.97%. Notably, our analysis reveals that detection algorithms struggle significantly when ideas are paraphrased into a simplified, non-expert style, contributing the most to the erosion of distinguishable LLM signatures.
Key Contributions
- First systematic evaluation of SOTA detectors distinguishing human vs LLM-generated scientific ideas across successive paraphrasing stages
- Demonstrates that iterative paraphrasing causes a 25.4% average detection performance drop, with simplified non-expert style contributing most to LLM signature erosion
- Shows that incorporating research problem context improves detection by up to 2.97%, suggesting semantic grounding helps attribution
🛡️ Threat Analysis
The paper focuses on detecting AI-generated content (LLM vs human scientific ideas) and systematically evaluates how iterative paraphrasing erodes distinguishable LLM signatures in detectors — a direct study of output integrity and AI-generated content attribution robustness.