SUMMARYThe privacy of users' data has become a big issue for cloud service. This research focuses on image cloud database and the function of similarity search. To enhance security for such database, we propose a framework of privacy-enhanced search scheme, while all the images in the database are encrypted, and similarity image search is still supported. key words: privacy-enhanced search, cloud service, content-based image retrieval (CBIR), homomorphic encryption, searchable encryption