The rapid evolution of open radio access network (O-RAN) technology has produced many innovations and increased adoption of drones across various industries, including delivery systems, search and rescue, and surveillance. However, as the adoption of drones becomes more widespread, there is an increased likelihood of security breaches, which can be disastrous, particularly in disaggregated scenarios. Compromised communication channels can make drone communications vulnerable to attacks by an adversary, leading to sensitive data leaks or disruption of services. This paper examines the current approaches to solve this problem and their associated drawbacks, such as requiring computationally expensive cryptographic operations unsuitable for resource-constraint drones. Following this, an efficient and secure scheme is proposed that employs chameleon hash functions to enable mutual authentication and key agreement between user and drone that allows access to real-time information. To demonstrate the protocol’s resilience against known security attacks, both an informal and formal analysis utilising Tamarin have been presented. A proof of concept has been implemented to display the feasibility of the solution along with a comparison to the state-of-the-art approaches.