# Blockchain Technology for Secure Communication and Formation Control in Smart Drone Swarms
###### Abstract  
Today, intelligent drone technology is rapidly expanding, particularly in the defense industry. A swarm of drones can communicate, share data, and make the best decisions on their own. Drone swarms can swiftly and effectively carry out missions like surveillance, reconnaissance, and rescue operations, without exposing military troops to hostile conditions. However, there are still significant problems that need to be resolved. One of them is to protect communications on these systems from threat actors. In this paper, we use blockchain technology as a defense mechanism against such issues. Drones can communicate data safely, without the need for a centralized authority (ground station), when using a blockchain to facilitate communication between them in a leader-follower hierarchy structure. Solidity has been used to create a compact, lightweight, and effective smart contract that automates the process of choosing a position in a certain swarm formation structure. Additionally, a mechanism for electing a new leader is proposed. The effectiveness of the presented model is assessed through a simulation that makes use of a DApp we created and Gazebo software. The purpose of this work is to develop a reliable and secure UAV swarm communication system that will enable widespread global adoption by numerous sectors. IoT; drone swarms; formation control; security; blockchain; smart contract; Gazebo; mavsdk +
Footnote †: journal: _Future Internet_  
effective decisions, which could, at best, lead to mission failure. A comprehensive review of these issues and the solutions researchers created to overcome them can be found in [6]. One of these solutions relies on the use of blockchains. Blockchain technology is an innovative and promising idea that can offer solutions to various problems in different sectors, including the defense industry. Its undisputed, unmodifiable, and fully transparent environment in terms of transactions is attracting more and more users every day. Since its inception, researchers have focused their attention on the technology that underlies blockchains with the goal of employing it outside the finance industry. Works related to blockchains, as well as the areas they focus on, can be found in [7; 8; 9]. Applications of blockchains in the Internet of Things (IoT), storage and data transfer, network security, and data privacy are some of the modern issues that concern researchers worldwide. Therefore, blockchains find applications in businesses, governments, the health sector, and even the military due to the security and transparency they offer. This technology is especially appealing to the military, where data and communication security are crucial. Research into the use of blockchain technology in drone swarms has huge implications for various industries and fields, including military, commercial, and political applications. Improved security, privacy, and trust among members, as well as better coordination and performance, are potential benefits of such systems. These studies may consequently result in a rise in the use and creation of technologies that alter how tasks like disaster relief and surveillance are carried out. In terms of ethical, legal, and social problems, research on blockchain technology and its use in the military operations of UAV squadrons in sensitive, high-risk areas is extremely important. For instance, the employment of autonomous drone swarms in military operations raises concerns about accountability and transparency in the decision-making process, the protection of human rights, and the risk of civilian casualties [10; 11]. Researchers can contribute to the creation of a more safe, open, and moral drone swarm system whose advantages will be distributed in a just and equitable way by finding solutions to these problems.