Portrait of Cai Xiaojuan

Cai Xiaojuan (蔡 暁娟, CJ)

Cybersecurity & AI | Kyushu University

About

I am a doctoral candidate at Kyushu University specializing in cybersecurity and artificial intelligence. My research focuses on detecting and defending against Advanced Persistent Threats (APTs), especially in post-compromise data exfiltration scenarios. I also work on reinforcement learning for penetration testing and secure AI applications.

Contact & Education

Email: cai.xiaojuan.575@s.kyushu-u.ac.jp

Current Education: Doctoral Candidate, Department of Information Science and Technology, Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Fukuoka, Japan

Awards

Publications

International Conferences (Peer-reviewed)

  1. Cai, Xiaojuan, Yaokai Feng, and Kouichi Sakurai (2021). “Sequential Detection of Cyber-attacks Using a Classification Filter”. In: 2021 IEEE Intl Conf on Dependable, Autonomic and Secure Computing, Intl Conf on Pervasive Intelligence and Computing, Intl Conf on Cloud and Big Data Computing, Intl Conf on Cyber Science and Technology Congress (DASC/PiCom/CBDCom/CyberSciTech), pp. 659–666. DOI: 10.1109/DASC-PICom-CBDCom-CyberSciTech52372.2021.00111
  2. Cai, Xiaojuan and Hiroshi Koide (2023). “New Perspectives on Data Exfiltration Detection for Advanced Persistent Threats Based on Ensemble Deep Learning Tree”. In: Proceedings of the 19th International Conference on Web Information Systems and Technologies (WEBIST). INSTICC, SciTePress, pp. 276–285. ISBN: 978-989-758-672-9. DOI: 10.5220/0012181200003584
  3. Cai, Xiaojuan, Lulu Zhu, Zhuo Li and Hiroshi Koide (2025). “Multi-Objective Policy Optimization for Effective and Cost-Conscious Penetration Testing”. In: Proceedings of the 21st International Conference on Web Information Systems and Technologies (WEBIST). INSTICC. (Accepted / In press)

Domestic Presentations (Orally)

  1. Cai, Xiaojuan, Kouichi Sakurai, Yaokai Feng: “Performance Investigation of an Intrusion Detection System Based on Sequential Artificial Neural Network Classifiers”. Information Processing Society of Japan, Kyushu Branch Conference, Saga University (Online), March 2, 2021.
  2. Cai, Xiaojuan, Hiroshi Koide: “Model Stealing in Large Language Models”. Summer Programming Symposium 2023: Programming with LLMs and the Future of AI, Kyushu University, Nishijin Plaza, September 12, 2023.

Journal

  1. Cai, Xiaojuan et al. (2025). “Detecting Advanced Persistent Threat Exfiltration with Ensemble Deep Learning Tree Models and Novel Detection Metrics”. IEEE Access, pp. 1–1. DOI: 10.1109/ACCESS.2025.3567772