Jianfeng Zhang


2025

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Stand on The Shoulders of Giants: Building JailExpert from Previous Attack Experience
Xi Wang | Songlei Jian | Shasha Li | Xiaopeng Li | Bin Ji | Ma Jun | Xiaodong Liu | Jing Wang | Jianfeng Zhang | Jie Yu | Feilong Bao | Wangbaosheng
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Large language models (LLMs) generate human-aligned content under certain safety constraints. However, the current known technique “jailbreak prompt” can circumvent safety-aligned measures and induce LLMs to output malicious content. Research on Jailbreaking can help identify vulnerabilities in LLMs and guide the development of robust security frameworks. To circumvent the issue of attack templates becoming obsolete as models evolve, existing methods adopt iterative mutation and dynamic optimization to facilitate more automated jailbreak attacks. However, these methods face two challenges: inefficiency and repetitive optimization, as they overlook the value of past attack experiences. To better integrate past attack experiences to assist current jailbreak attempts, we propose the JailExpert, an automated jailbreak framework, which is the first to achieve a formal representation of experience structure, group experiences based on semantic drift, and support the dynamic updating of the experience pool. Extensive experiments demonstrate that JailExpert significantly improves both attack effectiveness and efficiency. Compared to the current state-of-the-art black-box jailbreak method, JailExpert achieves an average increase of 24% in attack success rate and 2.7 times improvement in attack efficiency.

2011

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Thread Cleaning and Merging for Microblog Topic Detection
Jianfeng Zhang | Yunqing Xia | Bin Ma | Jianmin Yao | Yu Hong
Proceedings of 5th International Joint Conference on Natural Language Processing

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Using Cross-Entity Inference to Improve Event Extraction
Yu Hong | Jianfeng Zhang | Bin Ma | Jianmin Yao | Guodong Zhou | Qiaoming Zhu
Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies

2008

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A Chinese Word Segmentation System Based on Cascade Model
Jianfeng Zhang | Jiaheng Zheng | Hu Zhang | Hongye Tan
Proceedings of the Sixth SIGHAN Workshop on Chinese Language Processing