Image-based face detection CAPTCHA for improved security. - Brian M. Powell; Adam C. Day; Richa Singh 001; Mayank Vatsa; Afzel Noore (Int. J. Multim. Intell. Secur., 2010)

Face recognition CAPTCHA. - Gaurav Goswami; Richa Singh 001; Mayank Vatsa; Brian M. Powell; Afzel Noore (BTAS, 2012)

fgCAPTCHA: Genetically Optimized Face Image CAPTCHA 5. - Brian M. Powell; Gaurav Goswami; Mayank Vatsa; Richa Singh 001; Afzel Noore (IEEE Access, 2014)

FaceDCAPTCHA: Face detection based color image CAPTCHA. - Gaurav Goswami; Brian M. Powell; Mayank Vatsa; Richa Singh 001; Afzel Noore (Future Gener. Comput. Syst., 2014)

A multibiometrics-based CAPTCHA for improved online security. - Brian M. Powell; Abhishek Kumar 003; Jatin Thapar; Gaurav Goswami; Mayank Vatsa; Richa Singh 001; Afzel Noore (BTAS, 2016)

Attack-Resistant aiCAPTCHA Using a Negative Selection Artificial Immune System. - Brian M. Powell; Ekampreet Kalsy; Gaurav Goswami; Mayank Vatsa; Richa Singh 001; Afzel Noore (IEEE Symposium on Security and Privacy Workshops, 2017)