With the rapid development of Internet of Things (IoT), more and more IoT node devices are deployed, but the accompanying security problem cannot be ignored. Node devices at the network layer of IoT mainly communicate through wireless sensor networks. Compared with the Internet, they are more open and more vulnerable to network attacks such as denial of service. Aiming at the network layer security problem faced by wireless sensor networks, a network intrusion detection system based on sequence model was proposed to detect and alarm the network layer intrusion, which achieved higher recognition rate and lower false positive rate. Besides, aiming at the security problem of the node host device faced by wireless sensor network node devices, with the consideration of the node overhead, a host intrusion detection system based on simple sequence model was proposed. The experimental results show that, the two intrusion detection systems for the network layer and the host layer of wireless sensor network both have the accuracy more than 99%, and the false detection rate about 1%, which meet the industrial requirements. These two proposed systems can comprehensively and effectively protect the wireless sensor network security.

An anonymous network scanning system was proposed for traceability problem faced by network scanning tools during scanning. Firstly, the anonymous system was combined with the network scanning tool to implement anonymous scanning. Then, the local privatization of the system was implemented based on existing anonymous system. Thirdly, through traffic analysis, it was found that Nmap's multi-process scanning would become a single-process scan due to proxy chain, resulting in lower scan scan performance. Finally, a performance optimization scheme based on multi-Namp process concurrency was proposed, which divided the overall scan task into multiple scan tasks and assigned them to multiple separate Nmap processes in parallel. The experimental results show that the scanning delay of the performance optimization scheme is close to that of the normal scanning system, and achieves the purpose of improving the performance of the anonymous scanning system. Therefore, the optimized network anonymous scanning system hinders the traceability and improves the scanning efficiency.