This document proposes a lightweight searchable public key encryption (LSPE) scheme for cloud-assisted wireless sensor networks (CWSNs) to address issues with data confidentiality and energy efficiency. Existing searchable encryption schemes for CWSNs are computationally intensive and energy inefficient. The proposed LSPE scheme reduces computation costs compared to other searchable public key encryption schemes while still providing meaningful security. It constructs an LSPE based on star-like structures to achieve sub-linear search complexity. This allows keyword searches to be performed with lower energy consumption than existing schemes for CWSNs. The LSPE scheme divides the data retrieval process into setup, data collection, and data retrieval phases using algorithms like structure, encryption, and trapdoor to