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.

This paper proposed a stable and precise algorithm for 3D mesh model. Firstly, the algorithm, based on the original topology of mesh model, realized quick location of intersectional area of mesh curve by combining the intersection test of the layers of nodes bounding box. Then the algorithm utilized the improved triangular intersection algorithm to calculate the discrete intersectional segments and re-triangulates every intersectional triangle. Through building the topology of intersectional segments and triangles, the algorithm could quickly trace and pick up the discrete segments, and classify and combine the local area, and realize the precise Boolean operation. The algorithm could effectively deal with all kinds of instances, and could be implemented in programs easily. And the experimental results prove that the algorithm accords with requirements of the project.