Physical Layer Approach to Secure Visible Light Communication and Sensing

Abstract

Visible Light (VL) is a wireless technology that uses visible light (400 ~ 790 THz) as the medium to transmit information (i.e., visible light communication or VLC) or sense user's activities (i.e., visible light sensing or VLS) and it has now become a very active research topic in the area of wireless communication. While VL is expected to have a wide range of applications in the near future and there has been significant progress on the research, the security vulnerabilities of this technology have not been well understood so far. This situation may lead to the dangerous "zero-day attacks" issue when the technology is deployed in the near future. Thus, it's urgent to study the security vulnerabilities of VL and develop rigid countermeasures to these vulnerabilities.

In particular, due to the extremely short wavelength of visible light, the VL channel presents several unique characteristics than its radio frequency counterparts, which imposes new features on the VL security. Taking a physical-layer security perspective, the first proposed research of this exploratory dissertation attempts to investigate the intrinsic confidentiality of VLC communication as induced by its special channel characteristics. By exploiting the intrinsic linear superposition properties of VL, the second proposed research of this exploratory dissertation aims to design a signal-level always-on spoofing detection framework VL-Watchdog to secure the VL system from spoofing attack. The results reveal that due to the different types of reflections (specular and diffusive), the VL system becomes more vulnerable at specific locations where strong reflections exist, and the proposed VL-Watchdog was numerically evaluated under different factors and it was proved to be effective for VL spoofing attack detection.