1. Introduction
Biometric verification systems have enabled magnitude of access control applications including border control, smartphone access, banking, and finance applications. Fingervein biometric characteristics are widely deployed in various applications, particularly in banking sector. Fingervein biometrics represent the vein structure underneath the skin of the finger, which can be captured using near-infrared sensing. The blood flow in the fingervein absorbs near-infrared light and appears dark compared to the neighborhood region, indicating the visibility of the fingervein (refer Figure 1). The fingervein structure has been shown to be unique [1], [34], [28] between fingers of same data subject and between the data subjects. Compared to other biometric characteristics, fingervein biometrics are known for their accuracy and usefulness, and are less vulnerable to distortion. Furthermore, fingervein biometrics provide a natural way of protecting biometric features, as they reside inside the skin and thus more challenging to spoof.