Enhancing Cloud Image Retrieval Efficiency through Secure Optimization

There is a growing trend of using public clouds for image search outsourcing. However, privacy issues arise when image datasets are directly outsourced to untrusted clouds. Recently, a number of secure image retrieval techniques have been put forth. Nevertheless, the majority of them demand input from image owners in order to create secure indexes, wasting a significant amount of their computational power. Numerous approaches are put forth to address this issue; however, their search accuracy is poor when applied to large datasets. We present the first secure image retrieval scheme in this paper that addresses these two issues at the same time to achieve more precise search results. To reduce search time and image owner costs, we allow cloud servers to locally build a reliable hierarchical index graph using the encrypted image features. Moreover, parallel construction and updating of the secure index is possible. We offer a security analysis of the suggested plan.