{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T21:16:16Z","timestamp":1771708576099,"version":"3.50.1"},"reference-count":23,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2022,1,20]],"date-time":"2022-01-20T00:00:00Z","timestamp":1642636800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Network"],"abstract":"<jats:p>This article highlights challenges associated with securing visible light communication (VLC) systems by using physical layer security (PLS) techniques. Motivated by the achievements in PLS studies for radio frequency (RF) communication, many PLS techniques for VLC systems were also rigorously investigated by tailoring the RF techniques to the VLC environment. However, careful consideration of the inherent differences between RF and VLC systems is still needed. By disregarding these differences, an eavesdropper could be given an opportunity to wiretap the VLC systems, even when PLS techniques are employed to protect them. Crucially, the fact that it is often not possible to know the number and locations of eavesdroppers in real VLC systems may allow eavesdroppers to devise various cooperative eavesdropping methods. By examining a few examples of the possible eavesdropper threats that can occur in VLC systems, this article offers novel insights into the vulnerabilities of state-of-the-art PLS schemes for VLC systems. Although the focus of the paper is mostly on these weaknesses, some potential solutions are also briefly proposed with a view to stimulating discourse in the community.<\/jats:p>","DOI":"10.3390\/network2010004","type":"journal-article","created":{"date-parts":[[2022,1,20]],"date-time":"2022-01-20T22:51:06Z","timestamp":1642719066000},"page":"53-65","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Challenges in Physical Layer Security for Visible Light Communication Systems"],"prefix":"10.3390","volume":"2","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9924-822X","authenticated-orcid":false,"given":"Sunghwan","family":"Cho","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, Korea Military Academy, Seoul 01815, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2978-0365","authenticated-orcid":false,"given":"Gaojie","family":"Chen","sequence":"additional","affiliation":[{"name":"5GIC&6GIC, Institute for Communication Systems (ICS), University of Surrey, Guildford GU2 7XH, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9623-5087","authenticated-orcid":false,"given":"Justin P.","family":"Coon","sequence":"additional","affiliation":[{"name":"Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK"}]},{"given":"Pei","family":"Xiao","sequence":"additional","affiliation":[{"name":"5GIC&6GIC, Institute for Communication Systems (ICS), University of Surrey, Guildford GU2 7XH, UK"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1533","DOI":"10.1109\/JLT.2015.2510021","article-title":"What is LiFi?","volume":"34","author":"Haas","year":"2016","journal-title":"J. Light. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Tews, E., and Beck, M. (2009, January 16\u201318). Practical Attacks Against WEP and WPA. Proceedings of the WiSec \u201909\u2014Second ACM Conference on Wireless Network Security, Zurich, Switzerland.","DOI":"10.1145\/1514274.1514286"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Bloch, M., and Barros, J. (2011). Physical-Layer Security: From Information Theory to Security Engineering, Cambridge University Press.","DOI":"10.1017\/CBO9780511977985"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1195","DOI":"10.1109\/TIFS.2017.2656462","article-title":"Secrecy Outage Analysis for Downlink Transmissions in the Presence of Randomly Located Eavesdroppers","volume":"12","author":"Chen","year":"2017","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3026","DOI":"10.1109\/TIFS.2019.2912074","article-title":"Secrecy Performance Analysis of Wireless Communications in the Presence of UAV Jammer and Randomly Located UAV Eavesdroppers","volume":"14","author":"Tang","year":"2019","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Mostafa, A., and Lampe, L. (2014, January 10\u201314). Physical-layer security for indoor visible light communications. Proceedings of the 2014 IEEE International Conference on Communications (ICC), Sydney, Australia.","DOI":"10.1109\/ICC.2014.6883837"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1806","DOI":"10.1109\/JSAC.2015.2432513","article-title":"Physical-Layer Security for MISO Visible Light Communication Channels","volume":"33","author":"Mostafa","year":"2015","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Mostafa, A., and Lampe, L. (2014, January 8\u201312). Securing visible light communications via friendly jamming. Proceedings of the 2014 IEEE Globecom Workshops (GC Wkshps), Austin, TX, USA.","DOI":"10.1109\/GLOCOMW.2014.7063485"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Zaid, H., Rezki, Z., Chaaban, A., and Alouini, M.S. (2015, January 14\u201316). Improved achievable secrecy rate of visible light communication with cooperative jamming. Proceedings of the 2015 IEEE Global Conference on Signal and Information Processing (GlobalSIP), Orlando, FL, USA.","DOI":"10.1109\/GlobalSIP.2015.7418381"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1109\/JSAC.2017.2774429","article-title":"Physical-Layer Security in Multiuser Visible Light Communication Networks","volume":"36","author":"Yin","year":"2018","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2633","DOI":"10.1109\/TIFS.2019.2904440","article-title":"Enhancement of Physical Layer Security With Simultaneous Beamforming and Jamming for Visible Light Communication Systems","volume":"14","author":"Cho","year":"2019","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2918","DOI":"10.1109\/TWC.2018.2804390","article-title":"Securing Visible Light Communication Systems by Beamforming in the Presence of Randomly Distributed Eavesdroppers","volume":"17","author":"Cho","year":"2018","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1495","DOI":"10.1109\/TIFS.2020.3036806","article-title":"Zero-Forcing Beamforming for Active and Passive Eavesdropper Mitigation in Visible Light Communication Systems","volume":"16","author":"Cho","year":"2021","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Yesilkaya, A., Cogalan, T., Erkucuk, S., Sadi, Y., Panayirci, E., Haas, H., and Poor, H.V. (2020, January 17\u201320). Physical-Layer Security in Visible Light Communications. Proceedings of the 2020 2nd 6G Wireless Summit (6G SUMMIT), Levi, Finland.","DOI":"10.1109\/6GSUMMIT49458.2020.9083799"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2840","DOI":"10.1109\/TWC.2013.040413.120972","article-title":"Optimal Cooperative Jamming for Multiuser Broadcast Channel with Multiple Eavesdroppers","volume":"12","author":"Yang","year":"2013","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1109\/TCE.2004.1277847","article-title":"Fundamental analysis for visible-light communication system using LED lights","volume":"50","author":"Komine","year":"2004","journal-title":"IEEE Trans. Consum. Electron."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1109\/TIFS.2013.2296991","article-title":"Physical Layer Security of Maximal Ratio Combining in Two-Wave With Diffuse Power Fading Channels","volume":"9","author":"Wang","year":"2014","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3088","DOI":"10.1109\/TIT.2010.2048445","article-title":"Secure Transmission With Multiple Antennas I: The MISOME Wiretap Channel","volume":"56","author":"Khisti","year":"2010","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Marin-Garcia, I., Guerra, V., and Perez-Jimenez, R. (2017). Study and Validation of Eavesdropping Scenarios over a Visible Light Communication Channel. Sensors, 17.","DOI":"10.3390\/s17112687"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1988","DOI":"10.1109\/TGCN.2021.3092146","article-title":"Cooperative Beamforming and Jamming for Secure VLC System in the Presence of Active and Passive Eavesdroppers","volume":"5","author":"Cho","year":"2021","journal-title":"IEEE Trans. Green Commun. Netw."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Pham, T.V., and Pham, A.T. (2016, January 20\u201322). On the secrecy sum-rate of MU-VLC broadcast systems with confidential messages. Proceedings of the 2016 10th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP), Prague, Czech Republic.","DOI":"10.1109\/CSNDSP.2016.7573901"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"7789","DOI":"10.1109\/TWC.2018.2871055","article-title":"Secrecy Performance of Multi-User MISO VLC Broadcast Channels With Confidential Messages","volume":"17","author":"Arfaoui","year":"2018","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/OJCOMS.2020.3041930","article-title":"Visible Light Communications via Intelligent Reflecting Surfaces: Metasurfaces vs Mirror Arrays","volume":"2","author":"Abdelhady","year":"2021","journal-title":"IEEE Open J. Commun. 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