Maintaining the integrity of data, privacy, and security against cyber assaults is critical in the world of wireless sensor networks (WSNs). A key component in guaranteeing safe intra-network communication is substitute re-encryption, or SRE. Nonetheless, the ongoing difficulties facing current SRE solutions include processing delays brought on by the need to transport a significant amount of data to the intermediary for re-encryption as well as the computing demands of asymmetric cryptography. In order to improve the secure communication between network nodes and an external data server, this paper presents a novel SRE scheme that is carefully tailored for WSNs. In order to minimize computational costs during SRE operations and conserve energy for resource-constrained nodes, the proposed SRE scheme integrates lightweight symmetric and asymmetric cryptographic algorithms to optimize efficiency. To enable secure key creation and distribution, the scheme also includes advanced handling of keys and digital certificates. This allows for smooth verification and scalable data sharing across the entities in WSN. This technique reinforces the confidentiality and integrity of data by maintaining sensor-node encrypted data and assigning secure re-encryption duties only to cluster heads. Thorough analyses of performance, security, and energy usage confirmed the system's resilience. The findings verify that the suggested SRE scheme greatly improves WSNs' overall network longevity, security, and efficiency.