A Survey on Modality Characteristics, Performance Evaluation Metrics, and Security for Traditional and Wearable Biometric Systems

Biometric research is directed increasingly towards Wearable Biometric\nSystems (WBS) for user authentication and identification. However, prior to\nengaging in WBS research, how their operational dynamics and design\nconsiderations differ from those of Traditional Biometric Systems (TBS) must be\nunderstood. While the current literature is cognizant of those differences,\nthere is no effective work that summarizes the factors where TBS and WBS\ndiffer, namely, their modality characteristics, performance, security and\nprivacy. To bridge the gap, this paper accordingly reviews and compares the key\ncharacteristics of modalities, contrasts the metrics used to evaluate system\nperformance, and highlights the divergence in critical vulnerabilities, attacks\nand defenses for TBS and WBS. It further discusses how these factors affect the\ndesign considerations for WBS, the open challenges and future directions of\nresearch in these areas. In doing so, the paper provides a big-picture overview\nof the important avenues of challenges and potential solutions that researchers\nentering the field should be aware of. Hence, this survey aims to be a starting\npoint for researchers in comprehending the fundamental differences between TBS\nand WBS before understanding the core challenges associated with WBS and its\ndesign.\n