SARDOS: Self-Adaptive Reaction Against Denial of Service in the Internet of Things

Denial of Service (DoS) is a common and severe security issue in computer networks. Typical DoS attacks overload servers with bogus requests, induce them to worthlessly commit resources, and even make them unable to serve legitimate clients. This is especially relevant in Internet of Things scenarios, where servers are particularly exposed and often equipped with limited resources. Although most countermeasures focus on detection and mitigation, they do not react to dynamically adapt victims' behavior, while at the same time preserving service availability. This paper presents SARDOS, a reactive security service that leverages detection mechanisms from different communication layers, and adaptively changes the operative behavior of victim servers while preserving service availability. We experimentally evaluated SARDOS with a prototype implementation running on an underclocked Raspberry Pi server. Our results show that, when running SARDOS, a server under attack displays considerably lower memory and CPU usage, while still ensuring (best-effort) fulfillment of legitimate requests.