Jienyan Fan: "Pattern Recognition Method on Detecting DDoS Attacks for Large-Scale Internet." Abstract: In recent years, distributed denial-of-service (DDoS) attacks have become a major security threat to Internet services. How to detect and defend against DDoS attacks is currently a hot topic in both industry and academia. In this talk, we propose a novel method to detect low-traffic DDoS attacks at edge routers of autonomous systems. The key idea is to exploit spatial correlation of DDoS attack traffic. Specifically, we regard edge routers as an image, whose pixels have two states, normal and attack. So the DDoS attack detection problem is modeled as a pattern recognition problem. That is, given observations of all pixels, we recognize which pixels are in attack state. Our simulation results show that the proposed framework can detect DDoS attacks even if the volume of attack traffic on each link is extremely small. Especially, for the same false alarm probability, our scheme has a detection probability of 0.97, while the scheme using threshold has a detection probability of only 0.17, which demonstrates the superior performance of our scheme. Our scheme is also very time efficient. Our simulation results show that 16 network traces, each of which has approximately 78M packets, are processed in 2.7 seconds, excluding the time to extract features from packets.