Themis: Accelerating the Detection of Route Origin Hijacking by Distinguishing Legitimate and Illegitimate MOAS

Route hijacking is one of the most severe security problems in today's Internet, and route origin hijacking is the most common. While origin hijacking detection systems are already available, they suffer from tremendous pressures brought by frequent legitimate Multiple origin ASes (MOAS) conflicts. They detect MOAS conflicts on the control plane and then identify origin hijackings by data-plane probing or even manual verification. However, legitimate changes in prefix ownership can also cause MOAS conflicts, which are the majority of MOAS conflicts daily. Massive legitimate MOAS conflicts consume many resources for probing and identification, resulting in high verification costs and high verification latency in practice. In this paper, we propose a new origin hijacking system Themis to accelerate the detection of origin hijacking. Based on the ground truth dataset we built, we analyze the characteristics of different MOAS conflicts and train a classifier to filter out legitimate MOAS conflicts on the control plane. The accuracy and recall of the MOAS classifier are 95.49% and 99.20%, respectively. Using the MOAS classifier, Themis reduces 56.69% of verification costs than Argus, the state-of-the-art, and significantly accelerates the detection when many concurrent MOAS conflicts occur. The overall accuracy of Themis is almost the same as Argus.