EverTracer: Hunting Stolen Large Language Models via Stealthy and Robust Probabilistic Fingerprint

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Xu, Zhenhua, Han, Meng, Xing, Wenpeng
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866909768333918208
author Xu, Zhenhua
Han, Meng
Xing, Wenpeng
author_facet Xu, Zhenhua
Han, Meng
Xing, Wenpeng
contents The proliferation of large language models (LLMs) has intensified concerns over model theft and license violations, necessitating robust and stealthy ownership verification. Existing fingerprinting methods either require impractical white-box access or introduce detectable statistical anomalies. We propose EverTracer, a novel gray-box fingerprinting framework that ensures stealthy and robust model provenance tracing. EverTracer is the first to repurpose Membership Inference Attacks (MIAs) for defensive use, embedding ownership signals via memorization instead of artificial trigger-output overfitting. It consists of Fingerprint Injection, which fine-tunes the model on any natural language data without detectable artifacts, and Verification, which leverages calibrated probability variation signal to distinguish fingerprinted models. This approach remains robust against adaptive adversaries, including input level modification, and model-level modifications. Extensive experiments across architectures demonstrate EverTracer's state-of-the-art effectiveness, stealthness, and resilience, establishing it as a practical solution for securing LLM intellectual property. Our code and data are publicly available at https://github.com/Xuzhenhua55/EverTracer.
format Preprint
id arxiv_https___arxiv_org_abs_2509_03058
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle EverTracer: Hunting Stolen Large Language Models via Stealthy and Robust Probabilistic Fingerprint
Xu, Zhenhua
Han, Meng
Xing, Wenpeng
Cryptography and Security
The proliferation of large language models (LLMs) has intensified concerns over model theft and license violations, necessitating robust and stealthy ownership verification. Existing fingerprinting methods either require impractical white-box access or introduce detectable statistical anomalies. We propose EverTracer, a novel gray-box fingerprinting framework that ensures stealthy and robust model provenance tracing. EverTracer is the first to repurpose Membership Inference Attacks (MIAs) for defensive use, embedding ownership signals via memorization instead of artificial trigger-output overfitting. It consists of Fingerprint Injection, which fine-tunes the model on any natural language data without detectable artifacts, and Verification, which leverages calibrated probability variation signal to distinguish fingerprinted models. This approach remains robust against adaptive adversaries, including input level modification, and model-level modifications. Extensive experiments across architectures demonstrate EverTracer's state-of-the-art effectiveness, stealthness, and resilience, establishing it as a practical solution for securing LLM intellectual property. Our code and data are publicly available at https://github.com/Xuzhenhua55/EverTracer.
title EverTracer: Hunting Stolen Large Language Models via Stealthy and Robust Probabilistic Fingerprint
topic Cryptography and Security
url https://arxiv.org/abs/2509.03058