Sustainable Data Management Strategies and Systems in Untrust Cloud Environments

The state-of-the-art strategies for the data privacy (e.g., personal information, user key, data sharing and exchanging management) are far from satisfied; Worse, a large number of data service providers are running in the "both athletes and referees" business model. We break the unfair "both athletes and referees" rule by introducing a distributed homomorphic key management service provider who collaborates with cloud service providers to provide fair data management for users. We then provide a construction of homomorphic key protocol to dispense user keys to cloud service providers and we are able to show that if the underlying El Gamal encryption is semantically secure then the proposed homomorphic key management protocol is secure against semi-honest adversary. Finally, a multi-tenant keyword search in cloud is presented as an immediate application of our homomorphic key management protocol.