On the Scalability of Delay-Tolerant Botnets

In this work, we present a novel intelligent botnet, called the delay-tolerant botnet, that intentionally adds random delays to command propagation and endeavours to avoid detection. We then study the scalability of delay-tolerant botnets. Specifically, we apply mathematical analysis to derive the average delay required to distribute a command to all bots in three types of command and control architectures: centralised, distributed, and hybrid delay-tolerant botnets. We find that in all cases, the delay increases approximately logarithmically with the number of bots, indicating that the delay-tolerant botnets are scalable. Finally, we verify the analytical results by simulations