REPORT Motlicek_Idiap-RR-18-2012/IDIAP Bi-Modal Authentication in Mobile Environments Using Session Variability Modelling Motlicek, Petr El Shafey, Laurent Wallace, Roy McCool, Chris Marcel, Sébastien face verification Speaker identification EXTERNAL PUBLIC Idiap-RR-18-2012 2012 Idiap Rue Marconi 19 July 2012 We present a state-of-the-art bi-modal authentication system for mobile environments, using session variability modelling. We examine inter-session variability modelling (ISV) and joint factor analysis (JFA) for both face and speaker authentication and evaluate our system on the largest bi-modal mobile authentication database available, the MOBIO database, with over 61 hours of audio-visual data captured by 150 people in uncontrolled environments on a mobile phone. Our system achieves 2.6% and 9.7% half total error rate for male and female trials respectively – relative improvements of 78% and 27% compared to previous results.