collaborators

14 papers

cs.CR2026

Defending against Adaptive Prompt Injection Attacks via Reasoning-enabled Task Alignment

Lipeng He, Yihan Wang, Jiawen Zhang +1

Indirect prompt injection attacks hijack LLM-based agents by embedding malicious instructions in third-party data that the agent retrieves during task execution. Existing defenses…

cs.AI2026

Beyond Similarity: Trustworthy Memory Search for Personal AI Agents

Jiawen Zhang, Kejia Chen, Jiachen Ma +7

Personal AI agents increasingly rely on long-term memory to provide persistent personalization across sessions. However, existing memory pipelines are largely driven by semantic si…

cs.LG2026

REFLECTOR: Internalizing Step-wise Reflection against Indirect Jailbreak

Jiachen Ma, Jiawen Zhang, Xiangtian Li +3

While Large Language Models (LLMs) demonstrate remarkable capabilities, they remain susceptible to sophisticated, multi-step jailbreak attacks that circumvent conventional surface-…

cs.AI2026

Evaluating Cognitive Age Alignment in Interactive AI Agents

Yifan Shen, Jiawen Zhang, Jian Xu +4

While agentic AI and its core multimodal large language models (MLLMs) have demonstrated remarkable promise in language and visual reasoning across domains ranging from daily life…

cs.CR2026

Mitigating Many-shot Jailbreak Attacks with One Single Demonstration

Kejia Chen, Jiawen Zhang, Boheng Li +6

Many-shot jailbreaking (MSJ) causes safety-aligned language models to answer harmful queries by preceding them with many harmful question-answer demonstrations. We study why this a…

cs.AI2026

Confidence-Aware Alignment Makes Reasoning LLMs More Reliable

Kejia Chen, Jiawen Zhang, Yihong Wu +5

Large reasoning models often reach correct answers through flawed intermediate steps, creating a gap between final accuracy and reasoning reliability. Existing alignment strategies…

cs.CY2026

From Pre-trained Models to Large Language Models: A Comprehensive Survey of AI-Driven Psychological Computing

Huiyao Chen, Ruimeng Liu, Yan Luo +4

The intersection of artificial intelligence and psychological science has experienced remarkable growth, with annual publications expanding from 859 papers in 2000 to 29,979 by 202…

cs.LG2026

Understanding and Preserving Safety in Fine-Tuned LLMs

Jiawen Zhang, Yangfan Hu, Kejia Chen +7

Fine-tuning is an essential and pervasive functionality for applying large language models (LLMs) to downstream tasks. However, it has the potential to substantially degrade safety…

cs.LG2026

Safety at One Shot: Patching Fine-Tuned LLMs with A Single Instance

Jiawen Zhang, Lipeng He, Kejia Chen +4

Fine-tuning safety-aligned large language models (LLMs) can substantially compromise their safety. Previous approaches require many safety samples or calibration sets, which not on…

cs.CV2025

Token-Level Inference-Time Alignment for Vision-Language Models

Kejia Chen, Jiawen Zhang, Jiacong Hu +4

Vision-Language Models (VLMs) have become essential backbones of modern multimodal intelligence, yet their outputs remain prone to hallucination-plausible text misaligned with visu…

cs.LG2025

Q-resafe: Assessing Safety Risks and Quantization-aware Safety Patching for Quantized Large Language Models

Kejia Chen, Jiawen Zhang, Jiacong Hu +4

Quantized large language models (LLMs) have gained increasing attention and significance for enabling deployment in resource-constrained environments. However, emerging studies on…

cs.CV2025

SHAPE : Self-Improved Visual Preference Alignment by Iteratively Generating Holistic Winner

Kejia Chen, Jiawen Zhang, Jiacong Hu +4

Large Visual Language Models (LVLMs) increasingly rely on preference alignment to ensure reliability, which steers the model behavior via preference fine-tuning on preference data…

cs.CR2025

SecPE: Secure Prompt Ensembling for Private and Robust Large Language Models

Jiawen Zhang, Kejia Chen, Zunlei Feng +4

With the growing popularity of LLMs among the general public users, privacy-preserving and adversarial robustness have become two pressing demands for LLM-based services, which hav…

cs.CR2025

Activation Approximations Can Incur Safety Vulnerabilities Even in Aligned LLMs: Comprehensive Analysis and Defense

Jiawen Zhang, Kejia Chen, Lipeng He +7

Large Language Models (LLMs) have showcased remarkable capabilities across various domains. Accompanying the evolving capabilities and expanding deployment scenarios of LLMs, their…