## 7 Conclusions  
IoT applications play a major role in building new solutions for various real-world problems. They connect physical sensors, field control centers, and cloud systems to enable reliable and smart applications. Recently, IoT applications have been experiencing tremendous industrial interest due to their advantages. However, physical attacks, such as false injection attacks, are considered to be one of the main threats for the security of the devices in the Internet of Things. False data injection attacks are considered to be very crucial in sensitive networks where any small alteration in the data measurement could lead to a severe consequence. Therefore, it is crucial to employ a scheme that provides a filtering ability against false data injection attacks, taking into consideration all of the limitations of the sensors that comprise the networked system. Several attempts have been made to design such a scheme, but all of them face some challenges. The common limitation of the existing solutions is energy-related issues.  
This paper presented a lightweight, randomized watermarking filtering scheme (RWFS) that provides data integrity, along with data confidentiality, in a wireless sensor network for IoT applications.  
Figure 10: The delay analysis between RWFS (the proposed scheme) and the [PERSON] et al. scheme. The average execution time for each round was measured for a total of 10,000 rounds.  
The primary goal of this proposed scheme is to be an energy-efficient mechanism for securing such networks against data injection attacks. We employ a homomorphic encryption algorithm to protect end-to-end data confidentiality and a watermark to achieve en-route data filtering. The scheme uses a watermark that is generated and embedded into the original data sent by all source nodes in the network. The watermark is generated based on four features, including an encrypted payload, the secret shared key of the cluster, the sensor's identifier, and the data capture time of the individual sensor node. This watermark is then embedded into random places within the packet. These random places are generated using a PRNG function. After this, the watermarks are verified by the respective cluster head to ensure the integrity of the packets. For a testing purpose, we have simulated our scheme in comparison with the [PERSON] et al. scheme. [PERSON] et al.'s work uses a homomorphic MAC function to provide for end-to-end integrity, which is computationally expensive and takes more time during generation. Our experimental results proved that RWFS achieves better computational efficiency and consumes less energy.  
Conceptualization, A.A., M.A.-R., and Y.T.; Formal analysis, A.A.; Funding acquisition, A.A.; Investigation, A.A.; Methodology, A.A., M.A.-R., and Y.T.; Software, A.A.; Supervision, M.A.-R. and Y.T.; Visualization, A.A.; Writing (original draft), A.A.; Writing (review & editing), A.A., M.A.-R., and Y.T.  
This research was supported by a grant from the \"Research Center of the Female Scientific and Medical Colleges\", Deanship of Scientific Research, King Saud University.  
The authors would like to acknowledge the financial support of the \"Research Center of the Female Scientific and Medical Colleges\", Deanship of Scientific Research at King Saud University.  
The authors declare no conflict of interest.