Safeguarding Large Language Models in Real-time with Tunable Safety-Performance Trade-offs
João Fonseca, Andrew S Bell, Julia Stoyanovich · Qeios · 2025
Large Language Models (LLMs) have been shown to be susceptible to _jailbreak attacks_, or adversarial attacks used to illicit high risk behavior from a model. Jailbreaks have been exploited by cybercriminals and blackhat actors to cause significant harm, highlighting the critical need to safeguard widely-deployed models. Safeguarding approaches, which include fine-tuning models or having LLMs “self-reflect”, may lengthen the inference time of a model, incur a computational penalty, reduce the semantic fluency of an output, and restrict “normal” model behavior. Importantly, these Safety-Performance Trade-offs (SPTs) remain an understudied area. In this work, we introduce a novel safeguard, called SAFENUDGE, that combines Controlled Text Generation with “nudging,” or using text interventions to change the behavior of a model. SAFENUDGE _triggers during text-generation while a jailbreak attack is being executed_, and can reduce successful jailbreak attempts by 30% by guiding the LLM towards a safe responses. It adds minimal latency to inference and has a negligible impact on the semantic fluency of outputs. Further, we allow for tunable SPTs. SAFENUDGE is open-source and available through https://pypi.org/, and is compatible with models loaded with the Hugging Face transformerslibrary.