Analysis on security-related concerns of unmanned aerial vehicle: attacks, limitations, and recommendations

1.   Introduction

For ages, the advancement of technology is one of the most promising and fruitful evolution. Bundled with uncertainty, technical advancements are successfully providing reliable, affordable, and user-friendly solutions to the problems we face in everyday life. Although the future is unknown, digital innovation continues to shape the future-encouraging people to adopt new hobbies and ways of interacting with everyday work and people. In recent times, UAV (Unmanned Aerial Vehicles)/drones are among the most prominent and rapidly increasing areas of interest for industrial, military, and personal applications. Research conducted by CUAVI (China Unmanned Aerial Vehicle Industry) predicted that the market scope of small domestic UAVs would be approximately 75 billion Yuan in China by 2025 ^[1]. The FAA (Federal Aviation Administration) highlighted that almost 2.5 million drones are presently flying in the US that is likely to reach almost 7 million drones by 2020 ^[2]. This rise in UAV/drone usage is due to several factors, i.e., growing demand for live streaming, real-time video shooting, image capture capabilities, mobility, ease of usage, etc. The UAV/drones have also been used for small goods transportation and last-mile delivery as they are easy to deploy, require low maintenance, have unique hovering ability, and have high mobility. The UAV/drones are also proving to be very effective in the domain of security, surveillance, and rescue operations ^[3,4]. On the other hand, the security concerns of UAVs are quite concerning to the stakeholders. In one incident, the Iranian military was able to take down a U.S. Lockheed Martin RQ-170 Sentinel drone by jamming the UAV's control signals ^[5]. Due to the design limitations and hostile operational domain, developing a full-proof security module for UAV/drones is a challenge for security experts. In terms of UAV/drone history, the earliest record of a UAV/drone dates back to the 18th century ^[6]. Apparently, in 1849 the Australians used unmanned balloons filled with explosives to attack Venice in Italian ^[7]. In 1915, the British military used unmanned balloons for photographic-based surveillance in the Battle of Neuve Chapelle ^[8]. During the early 19th century, cameras were not very advanced and different methods were used to enhance the visibility of the photograph taken by a camera attached to these floating objects ^[8].

The United States commenced UAV development during the First World War. In 1916, the US developed the first pilotless aircraft that could fly a steered distance of 1000 yards. Later in World War Ⅱ, the US developed further advanced UAVs including the Curtiss N2C-2 drone and the Radio plane OQ-2 ^[9]. Despite a long history of military-based applications, UAVs were considered unreliable and expensive. However, in the 1980s this aspect began to change with the US leading the way to develop economical UAVs. In the 1990s and 2000, miniature and micro UAVs were introduced. During the 2000 afghan war, it was a Predator drone that located Osama bin Label in Afghanistan ^[10]. Although, UAV's were originally developed for military purposes. However, studies showed that it has a high potential in numerous domestic applications. In 2014, Amazon initially suggested using UAVs for delivery purposes ^[6]. Later UAVs/drone's potential was explored by several domestic domains i.e., agriculture ^[1,2], construction, law enforcement, search and rescue, photography for real state, cinematography, etc. With this exponential growth of the application domain, UAV/drone's security and privacy concerns became more severe. The core idea of this paper is to give readers an in-depth view of the rising security-related concerns of UAV/drones. To give a clear idea of these security and privacy concerns The rest of the paper is organized as follows. Section 2 covers the existing regulation for UAVs. In section 3 covers the classification of both drones and UAVs. Drone architecture and communication methods are discussed in section 4. Detailed discussion on the applications of drone/UAVs is discussed in section 5. Drone/UAV security vulnerabilities and threats are covered in section 6. Section 7 covers the existing threats for drones/UAVs. Existing solutions and countermeasures for UAV/drone security are discussed in section 8. The physical and logical attack countermeasures are discussed in section 9. The limitations of existing security measures are discussed in section 10. Section 11 covers a brief overview of drone/UAV open research areas. Recommendations for improving security and privacy-related concerns for drones/UAVs with a summary of the paper are presented in section 12. Section 12 also presents a comparison between this paper and recent survey papers. Section 13 concludes the article.

2.   Regulations

The licensing of UAV/drone is of paramount importance due to the associated privacy and security implications of their use. Governments all over the world are taking steps to licence these devices ^[11,12]. The danger unlicensed UAV/Drones over private property and sensitive military jurisdictionas and installations is grave. In some countries like Lebanon, unlicensed or illegal drones are often taken down and legal action is pursued against owners due to the grave security risks to government institutes and public safety ^[11]. According to BBC News (British Broadcasting Corporation) ^[13], the CAA (Civil Aviation Authority) and FAA ^[14] announced some basic drone operation codes for the owners to follow, some of these include:

● A requirement for users/operators to register their UAVs/drones and always carry the prof of registration when operating.

● A restriction not to exceed a flight height of 400 feet.

● A restriction from flying near airfields. If there is a need to operate a UAV/drone near an airfield, permission must be acquired in advance from the relevant authorities.

● Due to public safety concerns, UAV/drones must be operated carefully or legal action can be taken against the harmful actions of a UAV/drone operator

● UAV/drones with cameras are not allowed to fly within 50m of people, animals, structures, or vehicles.

● UAVs/drones must be flown within the operator's line of sight.

● UAVs/drones must not be flown at night without proper lighting.

The mentioned rules present a very general outline of UAV/drone operation. With the dramatic increase in the drone market in recent times, many countries and states have defined their own rules and regulations for the ownership and operation of UAVs/Drones ^[15].

A typical drone/UAV system has three main components. The first is the ground control station or ground command and control. Second is the communication link, which could be through satellite, telecommunication infrastructure, or even through another drone. The third component is the drone/UAV itself. Detailed discussion about the architecture of drones/UAVs will be covered in a later section. Three default methods for drone/UAV communication include Satellite, Radio Signal, and the Internet. As shown in Figure 1 ^[16] a drones/UAVs can be controlled or communicated through satellite, telecom infrastructure, and internet (i.e., IoTs, drones, UAV, etc.).

The most common frequencies for controlling UAV/drones from the ground are frequencies for license-exempt radio equipment. Table 1 highlight the most common frequencies for command and control link ^[17].

Further standardization by ISO (International Organization for Standardization) committee ISO/TC 20/SC 16 ^[18] is still working to finalize standards for operating UAV/drones.

3.   Classification

A drone can be defined as an unmanned aircraft that is controlled remotely or autonomously. A UAV flies without a pilot on board ^[19]. Every UAV is a drone; however, not all drones can be classified as UAVs.

3.1.   Drones classification

The term drone is typically referred to as remotely (autonomously) controlled aircraft. This definition could include both submarines and land-based autonomous vehicles. Based on their flying mechanics, flying drones can generally be classified into three main types ^[20].

● Multi-Rotor Drones or Rotary-wing drones: Their main feature is the Vertical Take-off and Landing (VTOL) ability. Additionally, their ability to hover and high maneuverability play an important role in different applications.

● Fixed-Wing Drones: These types of drones are energy efficient compared to rotary-based drones. This is due to their capability to fly at high speed and glide. These drones can carry heavy payloads. The only concern for these types of drones is the runway, as they are Horizontal Take-Off and Landing (HTOL) drones.

● Hybrid-Wing Drones: As the name suggest, these type of drones have both fixed and rotary wings. These drones use gliding ability to travel fast, while rotary to perform hovering-based tasks.

3.2.   UAVs classification

A UAV can fly remotely (autonomously) based on a ground command and control mechanism using a controller, mobile phone, or computer ^[21]. UAV's can be classified by their ability to fly autonomously over long distances. UAV control can be classified into three main types.

● Full autonomous control: Fully automated to perform different tasks.

● Remote supervised control: Based on tasks, the UAV can be automated and also operated by a human.

● Remote pilot control: Human-based remote command and control.

The referenced classifications have their own merits and demerits. Brief information regarding these drones/UAVs classifications can be seen in Table 2 ^[22].

Some recent research work prefer to classify drones/UAVs based on their altitude. Figure 2 shows drone/UAV classification based on their altitude with some common examples ^[23].

4.   Drone/UAV architecture and communication methods

A large variety of commercial and military UAVs/drones exist today. Most commercial UAVs/drones are low-cost and remotely controlled. Mini and micro UAVs are gaining popularity for both commercial military applications. However, there are limitations in their application due to size and weight considerations. Tier Ⅱ & Ⅲ UAVs/drones, have high resource requirements (refer to Figure 2). Almost every UAV/drone is equipped with a combination of sensors, GPS, CPU, communication module, and batteries as shown in Figure 3. Due to advancements in technology, many UAVs/drones are approaching a point where they are finding commercial and military applications. It is believed that the lack of software and hardware support are the two main issues affecting the realization of their full potential ^[24].

Even though dependable autonomous UAVs exist, the main objective is to achieve the mission with additional payloads (i.e., sensors, camera, etc.). UAVs for defense or military applications are tailored for specific objectives and those equipment are not openly available for commercial UAVs application. As shown in Figure 3, a typical UAV can be broken down into five components.

● Drone/UAV airframe: The airframe of a drone/UAV must be very simple, aerodynamic, lightweight, and a stable. Size and weight are a constraint for any UAV, so efficient use of space is critical.

● Onboard computer: Onboard CPU is the heart of a drone/UAV. The onboard computer serves as the collector, collaborator, and controller for flight, onboard equipment, and sensors (i.e., GPS, camera, accelerometer, gyros, magnetometer, pressure, etc.)

● Payload: Drones/UAVs are utilized for several different purposes. Drones/UAVs designed for public and commercial use have different payload attachments compared to those developed for military applications. Examples of payloads include sensors, high definition cameras, infrared sensors, heat sensors, radiation sensors, or any military mission-based equipment, etc.

● Communication system: Every drone/UAV requires a set of communication systems. Either remotely controlled or automated. Communication equipment (i.e., radio, modem, sitcom, etc.) guarantees uninterrupted communication between UAV and its ground base station.

● Battery: Different UAVs have different requirements for the power source. Power sources are based on their size, objective, and range. Most Mini and Micro UAVs use Lithium power batteries ^[25].

4.1.   Communication methods

Communication plays an integral part of both fully automated or remotely controlled UAVs. To engineer a suitable suite for UAVs, the communication protocols, communication network, and communication model play an integral part ^[26]. Several researchers have proposed different network architectures, antenna designs, and communication methods. As shown in Figure 4 there are three basic methods for UAV communication at different altitudes ^[27].

With the introduction of highly capable 5G networks, some issues like data rate, coverage, and latency can be addressed. The advancement in communication technology can play a significant role in positioning UAVs for critical missions. Some of the key parameters of the different communication technologies (including Wi-Fi and cellular communication) can be seen in Table 3 ^[28].

Most of the UAVs communicate based on LOS (Line of sight), but when it comes to high altitude UAV/drones, LOS-based communication (as in Table 3) is not suitable other than GPS. For BLOS (Beyond line of sight), Table 4 gives a brief overview of LEO (Low Earth Orbit), MEO (Medium Earth Orbit), and GEO (Geostationary Earth Orbit) satellites ^[29].

Communication plays a vital role in the UAV/drone role and its architecture. Based on the mission and architecture of the UAV/drone, different communication modules are installed. Several UAVs/drones can carry a wide variety of payloads or attached modules based on the operational requirements ^[26].

5.   Drone/UAV application areas

In the new scientific developments arena, UAVs/drone's potentials are on the higher side. The applications of UAVs cover a huge domain ranging from personal use to military applications as shown in Figure 5 ^[30]. Drones and UAVs can be equipped with several different sensors, cameras, and other payloads to perform many different tasks. UAVs/drones have over two hundred applications based on how they are used and what payloads they carry ^[31]. Due to rapid deployment, diligence, ability to reach areas where humans can't reach, risk, cost, mobility, and payload options, drone/UAV applications are always increasing and improving.

5.1.   Application domain

Drones/UAVs will play a key role in the coming future. As shown in Figure 5, the application areas for UAVs/drones are on the increase. Based on types and applications, they can be classified into diverse usage domains. Generally, drones/UAVs follow an architecture based on their application. Dividing them by domains can therefore be a very effective way of better understanding their architecture and peculiarities. Figure 6 gives a brief overview of their classification by domain ^[32,33]. From Figure 6, it is clear that each domain has its own security and privacy needs.

6.   Drone/UAV security vulnerabilities and threats

Drones/UAVs offer numerous benefits that have kept increasing with technological progress. However, some of them have limited operating resources and others create diverse security, privacy, and safety concerns ^[34,35]. Licensing, regularization, and various measures (over-sight) should be adopted to limit unnecessary of nepharious UAV-based photography. Authorities all over the world should ensure that the adoption of surveillance-regulating measures and regulations are a priority. As regards network security and risk analysis, network coverage provided by a UAV is not similar to any Wireless Sensor Network (WSN) or Mobile Ad-hoc Network (MANETs) ^[36]. This is due to resource constraints as UAV-based coverage is wider and broader as compared to WSN and MANETs. Concerning AAA (Authorization Authentication Accounting), the following guidelines can be effective for UAVs:

● Authorization: Assigning privileges to the controller of the UAV to avoid any hostile takeover with administrative rights.

● Authentication: There must be a rigid authentication method for UAVs to avoid unauthorized access and control.

● Accounting: In case of any illegal activity by a UAV/drone, the owner can be tracked down.

Mischievous or criminal entities can use drones/UAVs for conducting illegal surveillance, cyber-attacks, and initiating privacy threats individuals and organizations because of the ease of accessibility. Various mechanical and operational capabilities of drones/UAVs are being exploited for conducting malicious activities ^[37]. Such events make UAV/drone growth a double-edged sword, the effort to make them more secure and rigid also makes them more effective for malicious activities.

6.1.   Security concerns

Due to their portability, low cost, availability, maintenability, and maneuverability UAVs are a perfect choice for criminal activity. For example, terrorists and criminals use UAVs to conduct harmful activities and sabotage. The ability to carry a wide range of attachments makes UAVs effective couriers for harmful chemicals or explosive items. Additionally, their ability to reach places where humans cannot, makes them useful. They can carry anything, unnoticed or stealthily ^[38].

6.2.   Safety concerns

Security is not the only concern for drones/UAVs. Any drone flying over populated areas or property can malfunction and crash. Such crashes can be harmful to buildings and can injure people ^[39]. Such incidents have been reported all over the world. Human injuries due to a UAV/drone are unfortunately common. In April 2016, a UAV hit a passenger jet (British AirwaysBA727). Due to these accidents, a few public safety measures can be considered:

● Safety Feature: There is a high probability that a UAV/drone can be hacked or go out of control due to strong winds. Under such circumstances, there should be an option to shut it down or to regain control again.

● Weak Signal or jamming: Signal jamming makes UAVs/drones venerable to hacking and hijacking as part of a cyber-attack.

● Design/Architecture safety: Most of the UAV/drones that are easily accessible to the public are rotary-based types as shown in Figure 7.

These drones can have additional safety features as shown in some products in Figure 8. Understandably adding such measures affects the architecture and may introduce some performance concerns, but safety must be a higher priority. A standard should be introduced regarding safety measures for publically available drones/UAVs. Such standards should also include crash avoidance features.

6.3.   Privacy concern

Privacy concerns are rife due to the ease with which anyone can procure UAVs with high-definition cameras and gadgets. People can be easily recorded or observed within their private property without their knowledge. Per Canadian Public Safety (CPS), UAVs have generated quite a few safety, security, and privacy concerns ^[40]. Taking pictures or recording people without their consent has resulted in blackmail and other criminal activities. Legal policies regarding taking private photos or videos without consent using UAVs, flying through premises, or hovering at window level should be introduced to help regulate UAV operations.

7.   Existing threats for drones/UAVs

Due to a lack of standardization, several UAVs currently in the market have considerable design issues. One of the most concerning of these issues is the unavailability of wireless security ^[41].

Some researchers also conducted different types of cyber-attack on UAVs in a controlled environment to test the effects and vulnerability ^[49]. Such experiments include:

● DoS Attack: Researchers used parallel requests for controlling UAVs. The high amount of requests overloaded the response and crashed the UAV system.

● Buffer-Overflow: In such an attack, the researchers modified the packet request for controlling the drone/UAV and crashed the system responsible for controlling the drone/UAV.

● ARP Attack: In Address Resolution Protocol (ARP) attack, the researcher used the cache-poisoning approach and it resulted in the disconnection of the UAV from its controller.

Other than communication links or attacks on ground control, a different aspect of cyber-attack on UAV is the attack on the operating system (OS) or micro-controller unit of a UAV. In most cases, these OS for UAVs are very similar to smartphones OS. Due to this similarity, several attacks that are effective against smartphone OS are also useful on UAV systems ^[52]. With the advancement of technology and UAV, attack vectors on UAVs are on the rise. The probability of attack types can be unlimited in the current era of technology. Figure 9 shows the attacks that are being reported or being conducted successfully for educational purposes ^{[49,50,53,54,55,56,57]}. Among the attacks highlighted in the section, GPS spoofing is one of the most common cyber-attack on UAVs/drones. Among the most common type of GPS attacks, include signal jamming, de-authentication, and zero-day attacks.

8.   Existing solutions and counter measures for UAV/Drone security

The first counter-measure for resolving security threats on drones/UAV is classifying the attacks types, intended target, and objective of the attack. Table 6 shows some of the most proponent cyber-attacks conducted against UAVs/drones. The table also highlights the nature of the attack and some security measures against the attacks ^[57]. Most of the attacks highlighted in Table 6 target the authentication process of a UAV/drone. This highlights the need for improvement in the authentication method of a UAV/drone.

8.1.   Current countermeasures

The wireless-based communication network suffers from numerous security issues and threats. In recent times, machine learning (ML) based intrusion detection systems (IDS) have been quite successful against network threats. As machine learning-based solutions require higher resources, several researchers are working on how resources can be managed in ML-based IDS ^[58]. Blockchain is also among the most effective approach for UAV/drone security and privacy ^[11].

8.1.1.   UAV/Drone communication network security

Keeping up with the current requirements of network security ML-based IDS are among the most successful tools. Generally, IDS are categorized into three types:

● Rule-Based: These types of IDS are used in the UAV domain ^[59] and the objective is to identify false data-injection attacks, specifically those who target signal strength between UAV and ground control. Rule-based IDS can be effective against known attack patterns and techniques. Conversely, these types of IDS cannot detect the new or complex types of attacks and require human interaction to counter such attacks.

● Signature-Based: Some researchers have also used signature-based IDS on UAV. In a paper ^[60], the authors used a bio-inspired cyber-attack method that attacks air-born networks. Like rule-based IDS, signature-based IDS are also not good against unknown and complex attacks.

● Anomaly-Based: These types of IDS are used against jamming attacks in UAV networks ^[61]. Jamming attacks include DoS, DDoS, triggering malfunction, and sensors-based attacks. The only major issue for anomaly-based ML IDS is the high resource requirement.

As the number of UAVs/drones increase, quite a lot of different solutions for UNV communication network are proposed. Some papers ^[62] identified the physical layer issues in UAV communication network and proposed iterative algorithm based on optimizing methods showed an improved detection rate of attacks. Similarly, other papers have looked into ADS-B issues, line of sight issues, air-to-ground, eavesdropping, and air-to-air wireless communications. Some of the solutions proposed by researchers include using modulation, dual antenna, game theory-based algorithm, or Q-learning-based approaches. In addition to these methods, encryption for secure UAV communication is also an important aspect. Researchers have been looking to encryption methods that are not resources hungry. Since traditional encryption, methods do not consider resources and delay as an important factor ^[63]. Encryption can not only provide secure communication but can also be very effective in the authentication process of a UAV/drone.

8.1.2.   Data security

Data captured by a UAV/drone is aggregated onboard the UAV before it is transmitted out. This aggregation plays an important part in minimizing network traffic. However, this aggregation and encrypting data creates other issues. The symmetric cipher is not secure enough to counter advance attack methods and asymmetric cipher requires high computation and high resources. Asymmetric cipher also requires additional storage overhead. Due to these constraints, researchers are looking to secure, yet lightweight encryption methods for UAV/drone data security.

8.1.3.   Forensic approaches

Digital forensics can plan a vital role in identifying and countering different types of UAV attacks. In paper ^[64] authors presented a generic framework for NF (Network Forensics). The framework analysis data traveling through firewalls or IDS to identify any anomaly. The goal of the framework is not only to identify the anomaly but also to track back the source of the activity. Another paper ^[65] has suggested an NF framework involving DIP (Digital Investigation Process) with multiple hierarchical digital investigation methods. The approach presented in this paper follows two-tiers. The first tier involves assessment, countermeasure, data collection and analysis, the incident report, and event closure. Second-tier is an object-based sub-phase ^[66]. In addition, a UAV/drone forensic process can be broken down into three main steps as shown in Table 7 ^[67].

Similarly, several other researchers have proposed different methods to use forensic methods to counter complex and advanced attacks. The reason for highlighting the forensic method is that with time the type and objective of attacks are more complex and difficult to identify ^[68]. With the help of forensic, both perpetrator and method of attack can be identified. With the identification of attack type, appropriate countermeasures can be implemented to avoid any future incident.

9.   Physical and logical attacks countermeasures

As per the survey ^[69], between 2014 and 2017 incidents among airplanes and drones amplified from 6 to 93, which makes it very important for the authorities to address security and privacy issues for UAVs. Due to an increase in cyber-attacks on drones/UAVs, the government needs to introduce strict policies and standards to minimize these concerns. With the popularity of UAVs among the civilian population, attacks and illegal use of UAVs would likely proliferate. Civilian or domestic UAV countermeasures are divided into physical and local countermeasures. Physical countermeasures against UAVs can be seen in Table 8.

Keeping in view that logical countermeasure for urban use against UAVs is not high-end tech and limited in range and functionality. Table 9 outlines the logical countermeasures against UAV/drones in an urban environment.

9.1.   Military and government Counter-measure techniques

When it comes to military-based countermeasures, resources availability is often not in question. As discussed earlier, the use of UAVs/drones is not limited to surveillance, but they are capable of conducting attacks or used to pinpoint locations for an attack, making them dangerous tools on the battlefield. Some of the well-known drone/UAV countermeasures can be seen in Figure 10.

Militaries all around the globe are well equipped to handle UAV/drone-based threats. Figure 10 only highlights some of the well-known and publically available information on anti UAV/drones weapon systems. Military and Government based organizations use different methods to detect drones. They (UAV/drone) can be detected using audio, video, motion, thermal, radio, and RF-based methods. All these methods have their own merits and demerits.

Table 10 gives a brief overview of different UAV/drone detection methods ^[79,80,81]. UAV/drone can be detected based on audio, video, motion, thermal, radio, and RF-based methods. All these methods have their own merits and demerits as highlighted in Table 10.

10.   Security implementation limitations

Several limitations still exist in adopting and implementing rigid security methods for UAVs/drones. Table 11 highlights some of the main issues for UAV/drone security limitations ^[82,83,84]. Most of the mentioned limitations can be overcome by standardizing UAV/drone design, communication protocols, and basic factory default security suits.

11.   Open research areas

Based on the earlier sections, it is clear that a lot of work is still needed in improving UAV/drone security. Some of the areas that are open for research are listed in Table 12. Research areas listed in Table 12 can play an integral part in solving several UAV/drone security concerns ^[85,86].

12.   Recommendations and summary

Some recommendations to improve security and privacy for UAV/drones are shown in Tables 13 and 14. In Table 13 general recommendations which could help in improving UAV security and privacy are mentioned. While Table 14 enlist the most recent block-chain-based solutions for UAV security and privacy. Further, the authorities and industry need to put a combined effort into regularizing and standardizing UAVs/drones to counter security and privacy-related issues ^{[84,87,88,89]}.

Table 14 represent UAV's privacy and security solutions based on blockchain. Blockchain can provide very effective and enhanced security for UAVs/drones ^[90]. The only concern for blockchain-based solutions is the requirement of additional computational resources ^[91]. On the contrary, the enhancement in terms of security and privacy due to blockchain is more than adequate. The blockchain-based solution can be a very suitable option for UAVs specifically designed for defense and government usage.

Table 15 highlights the areas discussed in this paper and a comparison with some recent survey papers on UAVs/drones. In Table 15 the first column represents all the topics discussed in the paper and the first row represents the recent survey papers reference. To highlight the significance of this paper, Table 15 shows the topics discussed in other survey papers by a black dot in contrast with the eleven topics covered in this paper.

13.   Conclusions

The trend and exponential growth in the use of UAV/drones are giving birth to an era of autonomous aerial vehicles. UAV/drones offer numerous advantages to both civilian and military-based domains. However, this increase in use and easy availability has raised serious security and privacy-related concerns. Due to the flexibility, low cost, ease of deployment, and portability of these devices, they have become very useful tools for mischievous activities. Despite the availability of several countermeasures against the malicious use of these vehicles (UAV/drone), they are still very effective for carrying out harmful activities. Privacy issues with UAV/drones are also very significant. In this technological age, privacy is a major concern for individuals and organizations. This paper presented a comprehensive study of these (security and privacy) concerns including an overview of factors driving these concerns alongside with possible counter-measures. Different recommendations were also made in the paper including existing solutions based on blockchain. These solutions can provide UAV/drones with improved data integrity, authenticity, and accessibility.

Conflict of interest

The authors declare no conflict of interest.