## 4 Theoretical Background and Research Model  
In order to predict users' intention to use BBCA technology our theoretic model draws on Protection Motivation Theory along with the constructs of innovativeness, technology trust, and privacy concerns, Figure 1.  
Protection Motivation Theory (PMT) illustrates the way that people are motivated to react to health threats or risky behaviors, so named fear appeals [49]. Once these fear appeals arise, individuals use cognitive processes to interpret them in order to evaluate their own threat response [50]. A comprehensive literature review on PMT [51] pointed out that PMT was applied to a variety of topics of research, encompassing fields of interest other than health issues. Besides health issues and disease prevention, PMT has been extended to environmental concerns as well as privacy and security concerns, political issues, and others. The motivation concept of protection therefore covers any threat for which the individual can respond effectively [52]. Two cognitive mediating processes are used in PMT; the threat-appraisal and the coping-appraisal process, and two types of behavior are considered; the adaptive and the maladaptive. While adaptive behaviors are acts taken by an individual for self-protection, maladaptive behaviors are purposefully avoidance reactions in response to a fear appeal. Maladaptive behavior is a behavior that is not protective against the danger generated by the fear appeal [49, 52, 53]. Threat appraisal estimates the consequences of maladaptive  
Figure 1: Research model. behavior and comprises three elements: severity, vulnerability (the perceptions of threat), and maladaptive rewards (intrinsic and extrinsic) [52]. Coping-appraisal assesses the ability to handle the threat and prevent it. Coping-appraisal comprises three factors: Self-efficacy, Response efficacy (efficacy variables), and Response costs. Self-efficacy is the person's perceived ability to perform the adaptive response [52]. Perceived response efficacy is the faith that the adaptive response will be successful, that protecting action will indeed be efficient in protecting oneself or others. Response costs are all costs regarding the adoption of adaptive coping response. Although the threat appraisal component of the PMT consists of three components as indicated, for the purposes of this study only perceived vulnerability and perceived severity are used. This rests on the argument that a unified construct of response costs and rewards can be achieved since the value of risk behavior and the cost of implementing prevention measures is conceptually difficult to distinguish [54]. This explains why several PMT researches did not include response costs and rewards in the same model when investigating behaviors in informational privacy and security [55, 56, 57, 58]. Reference [59] argues that Protection Motivation Theory (PMT) demonstrates strong explanatory power and, thus, is a valuable method for explaining precautionary online behavior. However, several researchers have challenged this argument. For instance [60] states that social cognition models such as the PMT are problematic due to the vague nature of their constructs and cannot be tested since they focus more on analytic and rather than synthetic truths. On the contrary, previous research that has used PMT revealed the effectiveness of PMT to predict individuals' security behaviors regarding internet usage [57], both via computers [61], and smartphones [58]. With the inclusion of biometric authentication in modern smartphones, privacy protection has become increasingly important in securing user biometrics [62]. Being based on personal traits, whether physiological or behavioral, biometric systems erase certain privacy issues considering their use. Mainly these issues are:  
* Biometrics can be collected or shared without the permission of the specific user, without adequate knowledge, or without a specific purpose [63].