Drone swarm deployment has grown in popularity in recent years in a number of industries, including environmental monitoring and search and rescue. Ensuring the safety and effectiveness of drone path planning is a crucial difficulty in these operations, particularly in areas with lots of barriers. This paper addresses three primary subjects: energy efficiency, secure communication between drones in a swarm, and techniques for avoiding obstacles. We propose a system where drones employ a method to detect and navigate around obstacles while sharing route information with fellow drones in the group to optimize energy efficiency. This dependence on shared data, however, raises the possibility of third-party manipulation, where inaccurate information may cause mishaps and mission failure. We incorporate RSA-based Digital Signatures with PKI into the communication framework to counter this attack. This method protects the swarm from potential cyber-attacks in addition to ensuring the integrity of the data.