Krentz, Konrad-Felix; Meinel, Christoph; Graupner, Hendrik
Proceedings of the International Conference on Embedded Wireless Systems and Networks (EWSN 2017)
Like virtually all media access control (MAC) protocols for 802.15.4 networks, also ContikiMAC is vulnerable to various denial-of-sleep attacks. The focus of this paper is on countering three specific denial-of-sleep attacks on ContikiMAC, namely ding-dong ditching, pulse-delay attacks, and collision attacks. Ding-dong ditching is when attackers emit interference, inject frames, or replay frames so as to mislead ContikiMAC into staying in receive mode for extended periods of time and hence consuming much energy. Pulse-delay attacks are actually attacks on time synchronization, but can also be launched against ContikiMAC’s phase-lock optimization to cause an increased energy consumption. Lastly, in collision attacks, an attacker provokes retransmissions via jamming. In this paper, to counter these three kinds of denial-of-sleep attacks, we propose two optimizations to ContikiMAC. The dozing optimization, on the one hand, significantly reduces the energy consumption under ding-dong ditching. Beyond that, the dozing optimization helps during normal operation as it reduces the energy consumption of true wake ups, too. The secure phase-lock optimization, on the other hand, is a version of ContikiMAC’s phase-lock optimization that resists pulse-delay attacks. Additionally, the secure phase-lock optimization makes ContikiMAC resilient to collision attacks, as well as more energy efficient. We implemented and evaluated both optimizations using the Contiki operating system and OpenMotes.