Acoustic-Based Security: A Key Enabling Technology for Wireless Sensor Networks

Technological advances have proliferated in several sectors by developing additional capabilities in the field of systems engineering. These improvements enabled the deployment of new and smart products. Today, wireless body area networks (WBAN) are commonly used to collect humans' information, hence this evolution exposes wireless systems to new security threats. Recently, the interest by cyber-criminals in this information has increased. Many of these wireless devices are equipped with passive speakers and microphones that may be used to exchange data with each other. This paper describes the application of the watermark-based blind physical layer security (WBPLSec) to acoustic communications as unconventional wireless link. Since wireless sensors have a limited computation power the WBPLSec is a valuable physical layer standalone solution to save energy. Actually, this protocol does not need any additional radio frequency (RF) connection. Indeed, it combines watermarking and a jamming techniques over sound-waves to create secure region around the legitimate receiver. Due to their nature, wireless communications might experience eavesdropping attacks. The analysis proposed in this paper, addresses countermeasures against confidentiality attacks on short-range wireless communications. The experiments over the acoustic air-gap channel showed that WBPLSec can create a region two meters wide in which wireless nodes are able to communicate securely. Therefore, the results favor the use of this scheme as a key enabling technology to protect the confidentiality in wireless sensor networks.