“…e) Inability to protect against various threats [11], [22], [37], [42], [44], which smart mobile devices are susceptible to, like touch-logger/key-logger, liveness detection, mimic attacks, etc. f) Choosing a suitable set of biometric characteristics is a critical challenge in case of biometric authentication particularly when considering multi-modal biometric security schemes [13], [22], [33], [39], [46]. Designing reliable authentication systems capable of selecting or deciding on an appropriate biometric set exists.…”