AmbiSec: Securing Smart Spaces Using Entropy Harvesting

Following the vision of Ambient Intelligence (AmI), this paper introduces and evaluates a novel security scheme that takes the advantage of the unpredictable and erratic behavior of wireless communication to generate secret keys. The main advantage is that the secret key generation is applicable to every wireless device, independently of their hardware characteristics as it only requires a wireless interface and a human movement, which inherently affects the signal propagation within the physical environment. To analyze the applicability of this scheme, we implement and systematically evaluate the key generation using a wireless sensor network deployed in a real-world scenario. The analysis clarifies how different factors influence the amount of randomness collected from the physical environment, and it also shows that guessing attacks from an eavesdropper are negligible even if it is able to eavesdrop the complete wireless communication.