CASHEIRS: Cloud assisted scalable hierarchical encrypted based image retrieval system

Image retrieval has become an important function in many emerging computer vision applications e.g. online shopping via images, medical health care systems. More and more images are being generated and stored in public clouds. However, recent photo leakage events raise concerns about privacy leaks for images stored in public clouds. In this paper, we present an efficient scalable hierarchical image retrieval system (CASHEIRS) which provides privacy-aware image retrieval feature. CASHEIRS employs transformed Convolutional Neural Network features to improve image retrieval accuracy and an encrypted hierarchical index tree to speed up the query process. Extensive evaluations using Caltech256 and INRIA Holiday datasets show that CASHEIRS is more effective than three existing schemes. We also demonstrate its practicality on a mobile device.