A Survey of Research on CAPTCHA Designing and Breaking Techniques. - Yang Zhang; Haichang Gao; Ge Pei; Sainan Luo; Guoqin Chang; Nuo Cheng (TrustCom/BigDataSE, 2019)

Research on the Security of Visual Reasoning CAPTCHA. - Yipeng Gao; Haichang Gao; Sainan Luo; Yang Zi; Shudong Zhang; Wenjie Mao; Ping Wang 003; Yulong Shen; Jeff Yan (USENIX Security Symposium, 2021)

A Security Analysis of Captchas With Large Character Sets. - Ping Wang 027; Haichang Gao; Qingxun Rao; Sainan Luo; Zhongni Yuan; Ziyu Shi (IEEE Trans. Dependable Secur. Comput., 2021)

TransNoise: Transferable Universal Adversarial Noise for Adversarial Attack. - Yier Wei; Haichang Gao; Yufei Wang; Huan Liu; Yipeng Gao; Sainan Luo; Qianwen Guo (ICANN (5), 2023)

The robustness of behavior-verification-based slider CAPTCHAs. - Guoqin Chang; Haichang Gao; Ge Pei; Sainan Luo; Yang Zhang; Nuo Cheng; Yiwen Tang; Qianwen Guo (J. Inf. Secur. Appl., 2024)