Mitigating attacks against adaptation mechanisms in overlay networks

Walters, AAron R. M.S., Purdue University, May, 2006. Mitigating Attacks Against Adaptation Mechanisms in Overlay Networks. Major Professor: Cristina Nita-Rotaru. Performance-aware measurement-based overlay networks offer increased performance and resilience to benign failures for end-to-end communication. Adaptation mechanisms are a critical component of overlay network design, enabling distributed construction of efficient overlays for performance-demanding applications in heterogeneous Internet settings. These mechanisms dynamically optimize applicationcentric metrics such as latency, jitter, bandwidth, and loss rate. However, endsystems are more vulnerable than core routers, making overlay networks susceptible to malicious attacks coming from untrusted outsiders, and especially from trusted (but compromised) members of the overlay. Unlike many outsider attacks, insider (or Byzantine) attacks can not be prevented by simply deploying cryptographic authentication mechanisms. In this work, we identify and classify insider attacks against adaptation mechanisms in overlay networks and demonstrate several of them against a mature, operationally deployed overlay multicast system. The attacks target the overlay network construction, maintenance, and availability and allow malicious nodes to control significant traffic in the network, facilitating further attacks such as selective forwarding, traffic analysis, and overlay partitioning. We present a comprehensive defense framework to address the identified attacks, focusing on a critical component, reducing the number of bad or unnecessary adaptations. We demonstrate the effectiveness of the newly proposed techniques through real-life deployments and emulations conducted on the PlanetLab and DETER testbeds, respectively.