SafeMP: Using Mechanical Wave Communication for Safer Payment

The popularity of campus information intelligence aims to provide better applications and services. However, we found that a phenomenon that has brought great inconvenience to students is queuing when pay in smart campus which needs to be resolved urgently. For example, buying meals in the school cafeteria at lunch or dinner time, paying school tuition, and so on. Also the privacy security is the primary prerequisite for smart campus's mobile electronic payment while transaction information can be intercepted easily by Hacker or hidden HD camera. In this paper, we propose the SafeMP, a mobile security and multi-to-one payment system employing the mechanical-wave transmission to reduce queue time and improve efficiency. The biggest conundrum with implementing this system is how to separate the multiple aliasing signals. The SafeMP is designed with a key finding: although the multiple aliasing signals are irregular, coupling degree between different mechanical wave signals is highly stable. We divide our work into three parts. First, we present a novel compensation method addressing the attenuation with the transmission distance. In addition, we define the degree of coupling to discriminate the aliasing for mechanical wave in ever slot. Finally, we design the rules of orthogonal coding to further connect the data bitstream of each time slot and restore the complete information which transmitted by different user, then the information separated can be corresponded to correct user. Our evaluation results show that the transmission distance does not influence the performance of the SafeMP. The SafeMP achieves an average accuracy of 97%.