Secure and Smartphone-Assisted Reprogramming for Wireless Sensor Networks Based on Visible Light Communication

Abstract

During the period of over-the-air reprogramming, sensor nodes are easy to eavesdrop and even controlled by unauthorized person. That reminds us that security is key issue for over-the-air reprogramming. Most of previous studies discussed this problem from the aspect of data encryption, but give little consideration to the physical level. In this paper, we attempt to improve the security of reprogramming by changing the physical-level communication mode. We apply unidirectional Visible Light Communication (VLC) to the over-the-air reprogramming and use Commercial Off-The-Shelf device such as smartphone and sensor node to improve applicability. However, the unstable light source and low-cost light sensor make the procedure of reprogramming difficult. For this end, we put forward a novel reprogramming approach named ReVLC, which is twofold: firstly, we design a code block mechanism based on function similarity to reduce transmitting code. Secondly, we use compressing representation to optimize the Dual Header-Pulse Interval Modulation (DH-PIM) to save transmission time. The experiment results illustrate the effectiveness of ReVLC at the cost of extra 49.1% energy overhead compared with a traditional reprogramming approach.