Block-Based Method and Its System for Outsourcing Data by Using Onions of Encryption

With the rapid development and popularity of cloud computing, data outsourcing has become an essential widely used data service. Data owner uploads their private information to the cloud server and relies on the services that the cloud provides to execute some operations on data. When data is stored in the cloud, performing data retrieval while preserving confidentiality of data is a big challenge. In order to protect data confidentiality and security, the sensitive data need to be encrypted before outsourcing to the cloud. However, with the increasing number of encrypted data stored in the cloud, how to retrieve required information efficiently from the mass encrypted data is still a challenge urgently to be addressed. In this paper, a new ciphertext retrieval method is proposed to solve the above problem. In this method, the database is divided into several block encryption, and each block encryption is assigned to an index file correspondingly. The index files are encrypted with onion encryption, which allows the server to execute the queries while protecting data confidentiality. The experiment indicates that this encryption scheme can improve the efficiency of encrypted database retrieve.