## Related Work  
### Flying Ad-Hoc Network  
In flying ad-hoc network, the security and privacy are important because UAVs are always unattended. The primary security mechanisms for FANET emphasize authenticity, confidentiality and integrity of data via cryptography. A well-designed data protection mechanism can significantly reduce the probability of the data becoming compromised, irrespective of the malicious technique involved. There are a few studies dedicated to investigating the data protection issues for UAV networks. [PERSON] et al. [16], proposed a suite of cryptographic protocols for drones and smart objects. The protocols deal with three communication scenarios: one to-one, one-to-many, and many-to-one. In the first scenario, that is, one-to-one, the efficient encapsulation mechanism, a certificateless signcryption tag key, backs the authenticated key agreement in addition to offering non-repudiation and user revocation. The one-to-many scenario involves a certificateless multi-recipient encryption scheme, which allows a UAV to transmit privacy-intensive data to multiple smart objects. Lastly, UAVs are able to collect data from multiple smart objects in the \"many-to-one\" communication scenario. The protocol, however, finds it difficult to transmit a multitude of encrypted messages and at the same time assure privacy of the end devices. Such novel cryptographic mechanisms are efficient and secure. However, they are supposed to be used in group communication where nodes are of equal computational capability. A novel approach to mitigate the broadcast storm problem during the interest's dissemination is proposed by [PERSON] et al. [17]. The approach is based on a trust-aware monitoring communication architecture for flying named data networking. It makes use of the inter-UAV communication for checking the data authenticity on a particular UAV without disturbing the desired level of security. However, data privacy and caching policies are not taken into consideration in the proposed scheme.  
In order to resist the physical capturing of drones with minimum exposure of confidential data, [PERSON] et al. [18] proposed a saveless-based key management and delegation system for a multi-drone environment. Nevertheless, the proposed scheme is not compatible with devices such as UAVs equipped with limited on-board energy that hinder the potency of finding a proper key renewal period with low computation cost and more security guarantee. [PERSON] et al. [19] proposed a pairing-free approach for drone-based surveillance applications. However, this approach faces the user revocation problem in the case of a physical attack. In such a case, the intruders can access not only current but future information of the drones. In order to cater the forward secrecy problem in drones, [PERSON] et al. [20] proposed two construction schemes that achieve better performance in terms of the computational cost required by the recipient. However, the approach uses the elliptic curves and, thus, it suffers from high computational cost. Moreover, the proposed scheme is not validated through formal security analysis. In 2018, [PERSON] et al. [21] presented a pairing-free key insulated signature scheme in the identity-based setting for improving the computational and communication efficiency. Later, in 2019, [PERSON] et al. [22] also proposed a pairing-free and provably secure certificateless parallel key-insulated signature (CL-PKIS) scheme in order to secure the communication in the IIoT setting. However, because the scheme involves the concept of elliptic curve, it is not free from the issue of high computational cost. Moreover, the proposed schemes are not validated through formal security analysis.