# Security Challenges for Light Emitting Systems
## 1 Introduction  
The security of networks has become a major challenge in recent years. First, there is a need to keep information confidential, so that only authorized parties have access to it, and protect the information transmitted over the network [1], which can even cover the backup of files or passwords stored on computers that are connected online, as well as access to computer systems and applications. This problem may be solved by requiring users to utilize keys to access their workstations, password secure critical documents, and digitally sign their emails [1]. The second safety challenge involves the protection of the internet infrastructure. The purposes are to protect against attacks on the configuration of network devices, stealing networking resources and, consequently, maliciously jamming nodes or connections with disingenuous data that prevent legitimate messages from passing [1].  
One solution is visible light communication, a new emerging paradigm of wireless technology proposed in the beginning of 2000s [2]. This technology was designed as a point-to-point wireless communication link between an LED light and a receiver, equipped with a photo detection (PD) system. The transfer of rate depends on the digital technology used and, thus, on the light [3]. According to [4], the light communication system (LCS) incorporating white LED illumination has received considerable attention in the last decade. In the paper, the authors propose a handover algorithm for an internal cellular system to extend the bandwidth transmission. There are several studies on security, in many aspects,namely the physical layer, MAC layer, indoor communication, outdoor communication, inter-channel interference, etc. In [5], the paper identifies the physical characteristics of VLC systems with security relevance. It also summarizes all of the security techniques that have been proposed in the literature for VLCs to date, including the physical layer security (PLS), which is discussed from an information theoretic perspective, as well as availability and integrity issues. The paper also addresses issues of secure localization and key generation [5].  
Other articles have proposed solutions based on OFDM modulation, and how to exploit this modulation for the benefit of cryptography and noise during communications in the system [6]. In [6], the authors provide an overview of recent developments in Li-Fi physical layer security (PLS) and explains the main differences between Li-Fi PLS and RF PLS. Furthermore, the authors of [7] present a new key extraction procedure for orthogonal frequency division multiplexing (OFDM) schemes in an indoor setting. The methodology presented extracts keys at the media access control (MAC) and physical levels. Because each OFDM signal frame is encrypted with a distinct key, it provides excellent physical security. The authors of [8] also propose a Li-Fi access point (AP) structure that employs orthogonal frequency division multiplexing (OFDM) and a tunable optical coding/decoding technique based on the optical pulse delay in an optical delay line (ODL) loop vector to allow efficient mapping of OFDM-based data access and transfer. In this paper, we present a generalized BM method for protecting and making our network more secure, especially during this global health crisis. In terms of complexity, our improved method has a complexity of O(L\({}^{2}\)) for both encoding and decoding. Another advantage of this approach is that even if the intruder discovers the encryption algorithm, the intruder will be unable to decode a message since he/she needs the value of k to encode and decode it. According to our estimations, even if the approach changes, the error-correcting aspect will not alter.