云计算环境下加密图像检索

公共云存储服务为企业海量多媒体数据提供了廉价的存储空间和多种多样的访问方法．但考虑到隐私安全问题,企业多媒体数据必须加密存储在云端，然而目前的大多数加密体制都不支持在加密多媒体数据上直接运算，因此，如何有效地管理和检索密文数据成为具有挑战性的问题．针对云计算环境下加密图像检索问题，首先给出了其形式化定义以及隐私安全要求;然后提出了一种基于安全相似度运算的隐私保护检索方案．该方案预先构建描述加密图像内容的基于内容的索引，再通过安全相似度运算检索加密图像．安全分析和性能评估证明该方案是IND-CCA安全的，并能有效地实现对加密图像检索．

Privacy-preserving query over the encrypted image in cloud computing

In the emerging cloud computing paradigm, data owners become increasingly motivated to outsource their complex data management systems from local sites to the commercial public cloud for great flexibility and economic savings. For the consideration of users' privacy, sensitive images have to be encrypted before outsourcing, which makes effective data utilization a very challenging task. In this paper, firstly, we define the problem of privacy-preserving query over encrypted images in cloud computing. And to solve the problem, we design a computable encryption scheme based on vector and matrix calculations. The scheme pre-builds a feature-based index to provide feature-related information about each encrypted image, and then chooses the efficient image similarity measure as the pruning tool to carry out the retrieval procedure. Security analysis and performance evaluation show that the scheme is IND-CCA.