collaborators

11 papers

cs.CR2026

Capability-Routed Guard: Defending Large Reasoning Models Against Reasoning-Centric Jailbreaks

Yiyong Liu, Yixin Wu, Jun Sakuma

Large reasoning models (LRMs) expose a new safety failure mode: adversarial prompts can manipulate reasoning context, task decomposition, or capability interpretation so that harmf…

cs.CR2026

Differentially Private Synthetic Text Generation for Retrieval-Augmented Generation (RAG)

Junki Mori, Kazuya Kakizaki, Taiki Miyagawa +1

Retrieval-Augmented Generation (RAG) enhances large language models (LLMs) by grounding them in external knowledge. However, its application in sensitive domains is limited by priv…

cs.AI2026

Toward Safer Diffusion Language Models: Discovery and Mitigation of Priming Vulnerability

Shojiro Yamabe, Jun Sakuma

Diffusion language models (DLMs) generate tokens in parallel through iterative denoising, which can reduce latency and enable bidirectional conditioning. However, the safety risks…

cs.LG2026

Robust Deep Reinforcement Learning against Adversarial Behavior Manipulation

Shojiro Yamabe, Kazuto Fukuchi, Jun Sakuma

This study investigates behavior-targeted attacks on reinforcement learning and their countermeasures. Behavior-targeted attacks aim to manipulate the victim's behavior as desired…

cs.CL2026

Pattern Enhanced Multi-Turn Jailbreaking: Exploiting Structural Vulnerabilities in Large Language Models

Ragib Amin Nihal, Rui Wen, Kazuhiro Nakadai +1

Large language models (LLMs) remain vulnerable to multi-turn jailbreaking attacks that exploit conversational context to bypass safety constraints gradually. These attacks target d…

cs.CL2026

When Benchmarks Leak: Inference-Time Decontamination for LLMs

Jianzhe Chai, Yu Zhe, Jun Sakuma

Benchmark-based evaluation is the de facto standard for comparing large language models (LLMs). However, its reliability is increasingly threatened by test set contamination, where…