Efficient and secure data sharing with outsourced decryption and efficient revocation for cloud storage systems

摘要

Data access control is one of the major issues in cloud storage systems, especially when having multiple co-existing authorities requiring a multi-authority access control scheme. Existing multi-authority systems were able to achieve the required level of security and fine-grained access control, but since the cloud services can be accessed using devices with various computation capabilities, it is highly required to have a scheme with efficient encryption and decryption operations. In this paper, we propose a scheme able to achieve the desired level of security and fine-grained access control while having an efficient revocation operation. Moreover, we were able to increase the efficiency of the decryption operation by outsourcing most of the computation to a proxy-server without compromising the confidentiality of the data. In addition, we propose the usage of parallel processing in order to increase the efficiency of the various operations to efficiently use the computational power in low-end devices and the proxy-server. The analysis and simulation results show that ESS-ODER is efficient and provably secure.