Ciphertext retrieval against insider attacks for cloud storage

Abstract

With the improvement of awareness of data privacy, the user's sensitive data is usually encrypted before uploading them to the cloud. The searchable public-key encryption with keyword search provides an efficient mechanism to achieve the encrypted data retrieval without the complicated key management of symmetric encryption. Therefore, it is a critical technique on promoting secure and efficient cloud storage. Unfortunately, only one existing construction of ciphertext retrieval scheme is secure against inside keyword guessing attacks (KGA). In this paper, we build a framework to resist insider attacks. Additionally, we propose an efficient ciphertext retrieval with keyword search scheme with a designated tester (dCRKS), which is secure against inside keyword guessing attacks (KGA). Our security proof and performance analysis demonstrate that our scheme is practical for retrieval data stored in the cloud server.