Homomorphic-encryption-based separation approach for outsourced data management

Abstract

With the rapid application of cloud computing technologies, service and data outsourcing has become a practical and useful paradigm. In order to manage sensitive information in this outsourcing scenario, combined use of access control technologies and cryptography was proposed by many researchers. However, the rigid combination in existing approaches has difficulty in satisfying the flexible data management for diverse applications. In this paper, we advocate a separation methodology where an authorization policy is not required to be embedded into ciphertexts or keys during encrypting data, and can be linked to the ciphertexts at any time. Authorization is independently carried out as usually without involving encryption, and encryption plays a foundational mechanism without considering authorization. We propose a separation approach based on homomorphic encryption to realize outsourced data management, where an encryption procedure is separated from authorization, and dynamically integrated with authorization policy according to subjects' attributes at any time. © Springer-Verlag 2013.