# Blockchain Technology for Secure Communication and Formation Control in Smart Drone Swarms
## 3 Background
### Motivation  
The combination of blockchain technology and UAV swarms has the potential to significantly advance and address many problems in a variety of sectors, including the defense industry (Figure 4). Some of the greatest benefits of this concept are data integrity and security, transparent and controlled activities, autonomous decision making, and trust [24]. For drone swarms using blockchain technology, data integrity is crucial to ensuring the dependability and efficiency of cooperative operations. In order to prevent unwanted manipulation, the blockchain's immutability ensures that data generated by individual drones, including sensor readings, GPS locations, and mission status, are securely and permanently recorded on the blockchain. The swarm's data are further validated and synchronized via consensus methods, and data verification enables drones to cross-reference data with the blockchain to find errors or unlawful changes. The confidentiality and integrity of data during transmission are guaranteed by secure communication channels and data encryption. Timestamping provides accurate data synchronization, and smart contracts can be used to automate rule enforcement and data integrity checks. Additionally, the identity management and authentication capabilities of blockchains aid in validating the reliability of data sources, and the option of using public or private blockchains allows for customizing the level of transparency and privacy, depending on the particular use case. These factors work together to guarantee the reliability, security, and accuracy of the data created and shared inside the drone swarm, enabling cooperative and reliable operations for uses including surveillance, search and rescue, and more [25; 26]. In the context of drone swarms, log files [27] offer a variety of advantages, chief among which are their immutability and ability to produce traceable recordings of all actions taken by the drones in the swarm. These log files provide data recordings that are permanent and unalterable, protecting the integrity of the historical record when used in conjunction with blockchain technology or other tamper-resistant systems. For post-mission analysis, assuring responsibility, and confirming compliance with established procedures and regulatory standards, this immutability is essential. Each drone's actions and events, including takeoff and flight trajectories, sensor readings, and landing procedures, are painstakingly recorded and include cryptographic timestamps. This leaves a clear trail that makes it possible to recreate events and mission-related decisions with accuracy. This is especially useful for incident analysis and the development of improved safety measures. In addition to encouraging accountability, these traceable records make it easier to analyze data for optimization and provide insights into operational effectiveness and opportunities for development based on past performance data. Additionally, access to these log files can be strictly managed by blockchain-based authentication and access control, guaranteeing that only authorized users can access and examine the records and enhancing data security and privacy [28]. Moreover, by utilizing the data gathered by their IoT sensors and integrating blockchain technology for safe data exchange among drones in a swarm, the decision making, coor  
Figure 3: Layered structure of the blockchain architecture. This research focuses on the application and contract layers. dination, and optimization of collaborative operations are all significantly enhanced. A blockchain guarantees that crucial data are captured and shared among all swarm members in a transparent and tamper-proof manner, including drone locations, battery status, and environmental conditions. These shared data enable more accurate and well-informed decision making, allowing drones to successfully adapt to changing circumstances.