Research on the Improvement of RTS/CTS Mechanism in WAPI Protocol for Power Systems

The WAPI protocol has been widely used in power systems because of its excellent identity authentication mechanism, which effectively improves the reliability of data transmission in wireless local area networks (WLANs). However, the RTS/CTS mechanism in IEEE 802.11, the underlying protocol of WAPI, has security risks, and an attacker can realize DoS attacks by flooding RTS or forging RTS frames with oversized Duration to occupy channel resources. To address the above issues, an improved RTS/CTS mechanism for power system WLANs is proposed, which defends against RTS/CTS-oriented DoS attacks by introducing RTS/CTS lead frames and broadcast frames. The performance of the improved RTS/CTS mechanism is simulated and verified by the packet loss rate, throughput and transmission delay indexes. The results show that the improved RTS/CTS mechanism is able to effectively resist the RTS/CTS flooding attack and the oversized Duration attack, and improves the network security under the premise of guaranteeing the network throughput and communication delay.