# Decentralized and Secure Blockchain Solution for Tamper-Proof Logging Events
## 1 Introduction
This work arises as a new feature of the DRACSC system, the acronym in Spanish for Automatic Recovery and Configuration Device for Communication Systems, whose objective is to facilitate and centralize typical management tasks of network equipment (e.g., applying new configurations, installing firmware, creating, or restoring backups). To illustrate the relevance of secure logging, consider a real-world use case involving a network administrator managing router configurations (Figure 1). This administrator is authorized to execute sensitive actions, including adding routes to the routing table, creating user accounts, modifying firewall rules, and enabling promiscuous mode. Each of these actions carries inherent security risks; unauthorized modifications could potentially disrupt network traffic, grant unintentional access, expose systems to threats, or facilitate the interception of sensitive data [5]. This solution is part of a larger educational project, which was introduced in routers and switches in a network laboratory at the University of Huelva (Spain) and validated by students, teachers, and IT professionals [6; 7; 8]. In summary, the contributions of this work concerning the previous ones are the following: (i) to present a novel solution that allows immutable storage and recording of log events generated by network equipment; (ii) to solve the limitations of the current state of the art in terms of visibility and transparency of log records through public blockchains; (iii) to generalize the applicability of the system in other contexts through use cases that use transactions with and without metadata; and (iv) to provide the source code to the community in an open way to achieve transparency and move towards the establishment of a standard for log storage on the blockchain. In order to study the feasibility of this solution, two public blockchains (i.e., Cardano and Solana) have been selected, both with a level of maturity suitable for use in a production environment. The reason for choosing these blockchains is that they allow low-cost transactions with a high number of events, such as those that commonly occur in a communication network (i.e., our test scenario). Therefore, the authors have analyzed the response times through comprehensive experimentation with different rates of events per second. To this end, a complete software system has been developed to handle everything from data acquisition to persistence storage in public blockchains. Additionally, it includes a server for reading and processing the information effectively. This solution has been made available as open-source software, which enhances its transparency and facilitates its adoption by secure IT professionals, allowing them to establish customized functionalities and collaborate in its continuous development and improvement [9]. The article is structured as follows. Section 2 presents state-of-the-art solutions using blockchain for log storage. Section 3 describes the complete architecture of the system by separating it into three subsections with each of the different implementations. Section 4 presents the experiment and analyzes the impact of the solution in different scenarios. Section 5 provides the outcomes and corresponding discussions. Finally, Section 6 provides the conclusions, limitations, and future work.