EAGER: Towards Securing Visible Light Communications

可见光通信(VLC)由于其频谱免费、带宽丰富、传输速率高等优点，被认为是缓解5G时代射频频谱稀缺问题的一种有前途的小蜂窝解决方案。虽然近年来对VLC器件的研究取得了很大的进展，但VLC的安全方面到目前为止还没有得到很好的理解。与最初普遍认为的VLC本质上是安全的相反，因为可见光的传播是指向性的，并且可以被限制在封闭的空间内，最近的研究表明，VLC容易受到在光的直接光束之外，甚至在封闭空间之外的窃听者的窃听，并且对光源没有直接的视线(LOS)。此外，可见光传播的特殊光学性质还使VLC受到其他独特类型的攻击，如LOS阻止和欺骗。这些攻击在不久的将来大规模部署时，将对VLC系统构成严重威胁。这一迫切需要的项目旨在全面了解VLC的安全漏洞，并探索刚性和可证明安全的物理层应对措施的新知识。该项目将调查可见光多输入多输出(MIMO)对抗VLC特定攻击的能力。特别是，提出了一种友好干扰辅助的可见光MIMO波束形成结构，以对抗来自未知窃听者的窃听，即未知数量和未知位置的窃听者。然后，通过对每个用户使用更多的光电二极管(PD)并考虑到VLC通道状态信息的变化来扩展该体系结构，以有效地检测和减轻阻塞和欺骗攻击。研究人员将进一步研究多用户VLC MIMO系统的阻塞恢复能力，为不同优先级的用户提供差异化保护。此外，将开发一个MIMO VLC试验台来评估所提出的解决方案的性能。该项目还将执行一项综合教育计划，以扩大其对社会的影响，特别强调任职人数不足的群体和少数群体。

Due to its many nice features such as license-free spectrum, abundant bandwidth, and Gbps-level transmission rate, visible light communication (VLC) has been considered to be a promising small-cell solution for alleviating the RF spectrum scarcity problem in the 5G era. While the research on VLC devices has made significant progress in recent years, the security aspect of VLC has not been well understood so far. Contrary to the initial common belief that VLC is intrinsically secure because the propagation of visible light is directive and can be confined within a closed space, recent studies have revealed that VLC is vulnerable to eavesdroppers that are outside of the direct beam of the light, or even outside the closed space and do not have direct line-of-sight (LOS) to the light source. Moreover, the special optical nature of visible light propagation also subjects VLC to other unique types of attacks, such as LOS blocking and spoofing. These attacks will constitute serious threats to VLC systems when they are deployed in large scale in the near future. This EAGER project aims to obtain a comprehensive and urgently-needed understanding on the security vulnerabilities of VLC, and to explore new knowledge on rigid and provably-secure physical-layer countermeasures.This project will investigate the capability of visible light Multiple Input-Multiple Output (MIMO) in combatting VLC-specific attacks. In particular, a friendly-jamming-assisted visible light MIMO beamforming architecture is proposed to counter eavesdropping from unknown eavesdroppers, i.e., eavesdroppers of an unknown number and at unknown locations. This architecture is then extended by using more photodiodes (PDs) per user and accounting for the change of VLC channel state information, to effectively detect and mitigate blocking and spoofing attacks. The investigator will further study the blocking-resilience capacity of the multi-user VLC MIMO system to provide differential protection for users of different priorities. Moreover, a MIMO VLC testbed will be developed to evaluate the performance of the proposed solutions. The project will also carry out an integrated education plan to broaden its impact to the society, with a special emphasis on underrepresented and minority groups.