For real-time industrial wireless edge-enabled cyber-physical systems, this paper proposes an adaptive secure transmission mechanism under the large scale path loss to fight against randomly distributed illegal sensing devices. According to changes in the communication environment, the proposed scheme adaptively obtains the corresponding optimal power allocations and wiretap code rates. Specifically, by injecting artificial noise, an edge controller provides confidential control information for

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... a legitimate wireless sensing device and achieves non-confidential data service for a service subscriber, simultaneously. Considering whether the secrecy and non-confidential service rate constraints are met, a dynamic secrecy transmission mechanism is introduced to minimize secrecy outage probability (SOP) based on random channel realizations. The optimal power allocation for minimizing the SOP is derived through the efficient alternating optimization algorithm with numerical methods. Numerical results show that the proposed adaptive secure transmission strategy can efficiently utilize transmit power to achieve non-confidential information traffic without compromising the secrecy performance. INDEX TERMS Industrial wireless cyber physical security, adaptive secure transmission, secrecy outage probability.