Multimodal fusion vulnerability to non-zero effort (spoof) imposters

In biometric systems, the threat of “spoofing”, where an imposter will fake a biometric trait, has lead to the increased use of multimodal biometric systems. It is assumed that an imposter must spoof all modalities in the system to be accepted. This paper looks at the cases where some but not all modalities are spoofed. The contribution of this paper is to outline a method for assessment of multimodal systems and underlying fusion algorithms. The framework for this method is described and experiments are conducted on a multimodal database of face, iris, and fingerprint match scores.