Tech giant IBM is seeking to patent a system that will utilize distributed ledger technology (DLT) to address security and privacy concerns following the increasing popularity and usage of drones\u2014both commercially and recreationally. IBM first applied for the patent in March 2017. According to the document published by the U.S. Patent and Trademark Office (USPTO), the patent application is for a blockchain ledger that could be utilized to store information about unmanned aerial vehicles (UAVs) flights. The goal, according to the patent application, is to ensure that airspace controllers, regulatory bodies and even UAV owners can check and supervise the rising number of drones in the sky. The blocks will include data points related to drones flight patterns, including UAV location, manufacturer and model number, flying behavior, weather conditions, and even proximity to restricted zones. According to the patent application, "The data may be managed as part of a secure chain of data blocks (e.g., in blockchain networks) associated with the UAV that chronicles a status path of the UAV through its recent and\/or complete history. In this manner, the various characteristics and parameters of the UAV may be securely tracked using the secure chain of data blocks." In the proposed system, the permissioned blockchain could incorporate variable block time that can change in response to environmental triggers. For instance, in UAV no-fly or restricted fly zones\u2014national parks, military bases, and a predetermined radius around a major airport, transactions are added to the blockchain associated with the UAV more frequently in response to a triggering event, such as when the risk level is high (e.g., flying near one of the no-fly or restricted fly zones). Additionally, a smart contract may be implemented to determine that a UAV operator is meeting agreements regarding operation of the UAV. In contrast, drones that transport emergency medical supplies or perishable medication may be granted special permission to fly in restricted airspace without interference from the authorities. Regulators will be able to see from the blockchain data if a particular drone has the permission to fly over the area.