A comparison of key distribution schemes using fuzzy commitment and fuzzy vault within wireless body area networks

The fuzzy commitment scheme and the fuzzy vault scheme have been widely investigated by researchers in the distribution of symmetric keys within a Wireless Body Area Network (WBAN) for security purposes. Both schemes could use the same physiological signal (Electrocardiogram) for the same purpose (key distribution). To provide guidance to researchers, this paper conducts a comparative analysis of these two schemes to identify their similarities and differences, and contrast their relative merits and demerits. In the paper, we present their mathematical models first, and then compare the models step by step together with an analysis of their simulation performance. According to our analysis, we find that both the techniques follow common workflows to conceal a symmetric key in a transmitter and reveal the key in a receiver, respectively. On the other hand, the fuzzy commitment scheme has a more complicated process in obtaining ECG measurements than the fuzzy vault scheme; by contrast, its key concealing and revealing process is much simpler when compared to the fuzzy vault scheme. Besides a superior False Acceptance Rate (FAR) performance of the fuzzy commitment scheme, their False Rejection Rate (FRR) performance is comparable. Since the polynomial calculation and reconstruction are utilized in the fuzzy vault scheme, from the perspective of the computational complexity, the fuzzy commitment scheme is recommended for lightweight WBAN sensors.