# Individuals Identification Based on Palm Vein Matching under a Parallel Environment
## 1 Introduction  
Nowadays, individuals identification and verification through their unique physiological (fingerprint, face, iris, etc.) or behavioral (voice, gait, signature, etc.) traits by using biometric techniques are essential mechanisms in modern society. Governments and private stakeholders have increased their interest to adopt biometric-based identity management systems. In this context, market researchers estimate a significant growth for global biometrics. The global biometrics technology market is expected to reach $59.31 BN by 2025, according to a new study by Grand View Research [1]. This report forecasts the increasing use of biometrics technology in several areas with different applications enabling the industry to grow at a significant rate over the next six years. Some of these areas are consumer electronics to enhance customer experiences; government and defense services; banking and finance to increase efficiency and prevent fraud, among others. A biometric system is a pattern recognition system which aims to identify or verify the identity of a person by matching traits of individual anatomy, physiology or other behavioral characteristics from an acquired image (query) with the features of pre-stored images (template database) [2; 3]. Any physiologicalor behavioral attribute can qualify for being a biometric trait unless it satisfies the criteria such as: universality, distinctiveness, collectability, performance, acceptability, and circumvention [2]. Based on the criteria, there are several distinctive characteristics, or biometric traits, which have been studied and tested. Among them are: fingerprint [4; 5], face [6; 7], iris [8; 9], palmprint [10; 11], voice [12; 13], finger and palm vein [14; 15], gait [16; 17], signature [18], DNA [19; 20], and others. An extensive review of biometric technology is presented in [21]. Currently, fingerprinting technology is the most used due to the preliminary biometric technology as well as the low cost of imaging sensors. However, during the last few years, a considerable growth in terms of revenue has been evident for face, iris and vein recognition technologies [21]. In particular, techniques based on finger and palm veins for biometric recognition of people, also known as vascular biometrics, have all been emerging in recent years [22]. The vein recognition technique uses the blood vessels under the skin for individuals' identification. Especially in fingers and palms, veins present important biometric characteristics such as universality, distinctiveness, permanence, and acceptability. In addition, in comparison with other biometric features (e.g., fingerprint, face, gait, voice, and others), it has three distinct advantages [23]: (1) can only be captured in a living body, avoiding fraud with parts of deceased people or other non-presential fraud techniques; (2) is very difficult to copy or falsify; (3) does not suffer damages due to external factors, as the fingerprint suffers due to skin wear. Furthermore, the palm vein offers significant advantages such as high accuracy rates, high resistance to criminal tampering, speed of authentication and compactness in size [24], as it is shown in Table 1. These advantages guarantee the high security of this recognition method, which has greatly increased the attention of the scientific community. In this paper, we present a novel palm vein recognition method for individuals' identification. Particularly, the palm veins network is better than finger-vein because it is less susceptible to a change in skin color, unlike a finger or the dorsal hand. In addition, there are more vein patterns in palm images due to the fact that the geometry of the blood vessels are more complex comparing against fingers. Most of the works in palm vein recognition have been focused on palm vein extraction in recent years [15]. Geometry based approaches [25; 26] extract palm vein patterns by using spatial methods from segmented blood vessels.