An Adaptive Secret Key Establishment Scheme in Smart Home Environments

The characteristics of wireless transmission make the smart homes become vulnerable to kinds of malicious attacks, such as eavesdropping. To ensure the security of home area networks, cryptographic keys need to be established for smart home devices. Specifically, the lightweight physical layer key extraction schemes can be implemented. In practice, however, the key generation rate of the state-of-the-art schemes is low. To improve the rate, in this paper we propose an adaptive secret key establishment scheme for smart homes using the Received Signal Strength (RSS) measurements. Two smart home devices can adaptively quantize the collected RSS measurements and obtain the secret key. To illustrate the practicality of our scheme, we experimentally implement it using the Ralink WiFi cards based on the RT2870 chipset. In addition, we evaluate the randomness of the generated key by conducting the NIST randomness test experiment.