Secure Short-Packet Communications in Dual-Hop Cooperative IoT Networks with Multiple Eavesdroppers.

This paper studies the secrecy performance of short-packet communications in dual-hop cooperative Internet-of-Things (IoT) networks in the presence of multiple eavesdroppers. The best node selection (BNS) scheme is proposed to select the best IoT node for improving secure packet transmissions from a source to a robot destination under two intercepting scenarios at eavesdroppers such as non-colluding and colluding. Closed-form expressions for the average secrecy block error rate (SBLER) and secrecy throughput (STP) of the BNS scheme are derived, based on which the asymptotic analysis at high signal-to-noise ratio (SNR) regimes is also carried out. Simulation results show that the proposed BNS scheme outperforms the random selection one in terms of SBLER and STP. Moreover, the impacts of average SNR and the number of blocklengths on the system STP are also evaluated.