Test-Time Immunization: A Universal Defense Framework Against Jailbreaks for (Multimodal) Large Language Models
This addresses the security problem of jailbreak attacks for users of LLMs and multimodal LLMs, offering a more universal solution compared to existing tailored defenses.
The paper tackles the vulnerability of (multimodal) large language models to diverse jailbreak attacks by proposing Test-time IMmunization (TIM), a universal defense framework that adaptively detects and fine-tunes against attacks, achieving effective protection as demonstrated in extensive experiments.
While (multimodal) large language models (LLMs) have attracted widespread attention due to their exceptional capabilities, they remain vulnerable to jailbreak attacks. Various defense methods are proposed to defend against jailbreak attacks, however, they are often tailored to specific types of jailbreak attacks, limiting their effectiveness against diverse adversarial strategies. For instance, rephrasing-based defenses are effective against text adversarial jailbreaks but fail to counteract image-based attacks. To overcome these limitations, we propose a universal defense framework, termed Test-time IMmunization (TIM), which can adaptively defend against various jailbreak attacks in a self-evolving way. Specifically, TIM initially trains a gist token for efficient detection, which it subsequently applies to detect jailbreak activities during inference. When jailbreak attempts are identified, TIM implements safety fine-tuning using the detected jailbreak instructions paired with refusal answers. Furthermore, to mitigate potential performance degradation in the detector caused by parameter updates during safety fine-tuning, we decouple the fine-tuning process from the detection module. Extensive experiments on both LLMs and multimodal LLMs demonstrate the efficacy of TIM.