A Hierarchical PoW-Powered Access Mechanism for Shuffling-Based Moving Target Defense System

For DDoS attacks, Moving Target Defense (MTD) has emerged as a promising solution. However, existing MTD defense systems often overlook the issue of user access. In this paper, we implement a hierarchical Proof of Work (PoW) authentication mechanism for user access in a shuffling-based proxy-switching MTD system. Our mechanism integrates the PoW authentication with the proxy cluster architecture and dynamically adjusts the difficulty level of PoW based on information from multiple proxies. The mechanism was deployed on a real MTD defense system for performance evaluation. By adapting the PoW scheduling approach for MTD systems, the experimental results demonstrate that our mechanism can adapt to and leverage dynamic network structures. In terms of mitigating DDoS attacks and ensuring user experience, it shows improvements compared to directly migrating traditional methods.