Abstract : In unattended wireless sensor networks, users can store and retrieve data as needed. For efficient data transmission, data is often aggregated at an aggregator before being forwarded to the next layer node. Therefore, it is crucial to ensure the confidentiality and integrity of the data during transmission. End-to-end encryption and hop-by-hop encryption schemes often fail to address this issue. Direct homomorphic encryption schemes are also ineffective in cases of node capture. To ensure both confidentiality and integrity while maintaining data transmission efficiency, we propose a homomorphic encryption and homomorphic secret sharing (HS) scheme. Finally, a detailed analysis demonstrates the security and effectiveness of this scheme. Keywords : Wireless Sensor Networks, Data Aggregation, Security 1. Introduction In unattended wireless sensor networks (UWSNs), data sensed by sensor nodes is typically stored locally for extended periods, rather than being immediately sent to the sink node upon generation. Local data storage conserves energy consumed during data transmission, thus extending the node's lifespan. This stored data is retrieved as needed by mobile users or data collectors. In recent years, UWSNs have received increasing attention. Secure and efficient data retrieval has become a crucial issue in wireless sensor networks. Because past data accumulates over long periods, the data volume becomes substantial. Collecting each data point individually would be extremely time-consuming. Even if only summary data needs to be retrieved from each node, a one-to-one collection method is still inefficient. Therefore, aggregated collection is attractive. That is, data is forwarded to the collector as needed. However, this requires ensuring the security of the forwarding nodes. If a forwarding node is malicious, for example, by losing some data or modifying some aggregated results, the data cannot be retrieved correctly. Furthermore, forwarding nodes may expose data content for malicious purposes, leading to potential dangers. [Full text download available: Application of a Secure and Effective Data Aggregation and Retrieval Technology in Unattended Wireless Sensor Networks]