A Secure Optimum Distributed Detection Scheme in Under-Attack Wireless Sensor Networks
Abstract-We address the problem of centralized detection of a binary event in the presence of fraction falsiﬁable sensor nodes (SNs) (i.e., controlled by an attacker) for a bandwidth constrained under attack spatially uncorrelated distributed wireless sensor network (WSN). The SNs send their one-bit test statistics over orthogonal channels to the fusion center (FC), which linearly combines them to reach to a ﬁnal decision. Adopting the modiﬁed deﬂection coefﬁcient as an alternative function to be optimized, we ﬁrst derive in a closed-form the FC optimal weights combining. But as these optimal weights require a priori knowledge that cannot be attained in practice, this optimal weighted linear FC rule is not implementable. We also derive in a closed-form the expressions for the attacker “ﬂipping probability” (deﬁned in paper) and the minimum fraction of compromised SNs that makes the FC incapable of detecting. Next, based on the insights gained from these expressions, we propose a novel and non-complex reliability-based strategy to identify the compromised SNs and then adapt the weights combining proportional to their assigned reliability metric. In this way, the FC identiﬁes the compromised SNs and decreases their weights in order to reduce their contributions towards its ﬁnal decision. Finally, simulation results illustrate that the proposed strategy signiﬁcantly outperforms (in terms of FC’s detection capability) the existing compromised SNs identiﬁcation and mitigation schemes.
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