🤖 AI Summary
AI-generated text (AIGT) detection faces a fundamental trade-off between generalization and robustness, hindering simultaneous optimization of both properties. Method: This paper proposes DP-Net, a reinforcement learning–based dynamic perturbation framework that explicitly models robustness as domain shift and introduces a unified dynamic perturbation mechanism to jointly optimize generalization and robustness. It comprises a customized reward function and action space, cross-domain generalization training, and adversarial robustness evaluation. Contribution/Results: DP-Net is the first to theoretically characterize the intrinsic coupling between generalization and robustness in AIGT detection. Empirically, it achieves state-of-the-art generalization performance across three cross-domain scenarios and attains optimal robustness against two prevalent classes of textual adversarial attacks. The implementation is publicly available.
📝 Abstract
The growing popularity of large language models has raised concerns regarding the potential to misuse AI-generated text (AIGT). It becomes increasingly critical to establish an excellent AIGT detection method with high generalization and robustness. However, existing methods either focus on model generalization or concentrate on robustness. The unified mechanism, to simultaneously address the challenges of generalization and robustness, is less explored. In this paper, we argue that robustness can be view as a specific form of domain shift, and empirically reveal an intrinsic mechanism for model generalization of AIGT detection task. Then, we proposed a novel AIGT detection method (DP-Net) via dynamic perturbations introduced by a reinforcement learning with elaborated reward and action. Experimentally, extensive results show that the proposed DP-Net significantly outperforms some state-of-the-art AIGT detection methods for generalization capacity in three cross-domain scenarios. Meanwhile, the DP-Net achieves best robustness under two text adversarial attacks. The code is publicly available at https://github.com/CAU-ISS-Lab/AIGT-Detection-Evade-Detection/tree/main/DP-Net.