# The Concept regarding Vehicular Communications Based on Visible Light Communication and the IoT
## 2 Methodology and Design Parameters
### Proposal for Software Infrastructure and Architectural Components  
In accordance with the prospects for future use of Li-Fi networks for V2V interactions, the proposed algorithm validates and authenticates users in vehicles based on the queries it makes within the internal nomenclature, which includes all IDs and encryption codes related to users. The interaction between the device and the vehicle involves a database located at the level of the vehicle ECU infrastructure. The risk of information leakage is minimal due to the degree of encryption and the transmission of information through light,  
Figure 4: Architecture of the proposed visible light communication system at the road infrastructure level. the identifiers being encrypted at the level of the internal stack without generating an exact reference to a specific device and constantly reinitialized every time they are reintegrated into the system. Regarding the security protocol for VLC-based networks such as Li-Fi, the process by which this occurs takes places in several stages. Devices are verified before connecting to the network and, if a device is in range, it receives a query asking for an access code and its verification leads to the first process. When the code is valid, the data are checked for identifiers and for whether there have been any previous logins. When the device authenticates and authorizes itself, the data are encrypted and sent within the network, with the traffic on that network being constantly monitored. In addition to these aspects, there are functions dedicated to the additional protection of the network from possible external attacks or penetrations. Therefore, encrypting and transmitting data through a Li-Fi-type network can be achieved using a symmetric encryption algorithm. A symmetric encryption algorithm is based on the use of unique keys that encrypt and decrypt data. In a Li-Fi network, these keys are generated and distributed across the network to all devices. One example of an algorithm based on symmetric encryption is the advanced encryption standard (AES). According to specialist studies, it is considered one of the most viable and powerful algorithmic structures in terms of symmetric encryption, and it is used in more and more security standards and, now, in VLC [54]. The structure in this case could be implemented according to the following steps:  
1. The header is initialized and a cryptographic key is generated for each ID (i.e., for each device on the network or each device that should connect to it);
2. The AES algorithm is used to encrypt the data and transmit them via the Li-Fi network;
3. The unique cryptographic keys are then sent to the connected devices to enable the decryption of the received data. Their form being that of the MD5 hash function, the unique identifier generated for each vehicle in the network can be inserted into their headers;
4. The keys are used to decrypt the data when they are received by the connected device. The existence of new technologies dedicated to cryptography has a direct connection with quantum cryptography, which is advancing quickly around the world. Specifically, quantum cryptography involves quantum key distribution (QKD) and subsequent redistribution of a cryptographic key. Later, the degree of security can be proven by using new instantiations on the bases of computational complexity and processing with emerging quantum computers [55]. In QKD, the quantum key can be exchanged between network users in the form of light to increase security. When quantum sequences are iterated, they are measured post-processing to generate identical keys on both sides of the network. A first step in this direction is the QuINSiDa project, which is the first to incorporate a \"QKD over Li-Fi\"-type system [56]. This aspect makes QKD data transfer possible, which is more widely used in communications between buildings and offices.