  Unmanned aerial vehicles (UAV), an emerging architecture that embodies flying
ad-hoc networks, face critical privacy and security challenges, mainly when
engaged in data-sensitive missions. Therefore, message authentication is a
crucial security feature in drone communications. This paper presents a
Blockchain-based Efficient, and Trusted Authentication scheme for UAV
communication, BETA-UAV, which exploits the inherent properties of blockchain
technology concerning memorability and is immutable to record communication
sessions via transactions using a smart contract. The smart contract in
BETA-UAV allows participants to publish and call transactions from the
blockchain network. Furthermore, transaction addresses are proof of freshness
and trustworthiness for subsequent transmissions. Furthermore, we investigated
their ability to resist active attacks, such as impersonation, replaying, and
modification. In addition, we evaluate the gas costs associated with the
functions of the smart contract by implementing a BETA-UAV on the Ethereum
public blockchain. A comparison of the computation and communication overheads
shows that the proposed approach can save significant costs over traditional
techniques.
