Improved collusion-resisting secure nearest neighbor query over encrypted data in cloud

摘要

Securely performing nearest neighbor query over encrypted data in cloud is an important topic in the area of cloud computing, for whichWang et al recently put forward a scheme (ie, CloudBI-II) to address the challenging security problem: resisting the collusion of cloud server and query users. In this paper,wepropose an efficient attack method that indicatesCloudBI-IIwill reveal the difference vectors under the collusion attack. Furthermore, we show that the difference vector disclosure will result in serious privacybreach and, thus, attain an efficient attackmethodto break CloudBI-II. Namely, CloudBI-II cannot achieve their declared security. Through theoretical analysis and experiment evaluation,weconfirm that our proposed attack approach can fast recover the original data from the encrypted data set in CloudBI-II. Finally, we provide an enhanced scheme that can efficiently resist the collusion attack.