Research On Data Cloud Storage Encryption Access Control Scheme

The technology of data encryption is the origin of communication security andcomputer security. The process of data encryption is enforced by cryptographicalgorisms with different forms and math theories, which completes the highest securewith fewest costs. Data encryption is a highly optimized way to protect the confidenceof data in general.To use cryptographic on information security in hierarchy, researchers propose thetechnology of hierarchical encryption access control, which encrypts the data indifferent secure layers by different keys in hierarchy. Only the authorized users canderive the right data keys by their own secret information. So, the technology of keymanagement is used to resolve the problem of access control.The paper does the work which contains the improvement of hierarchicalencryption access control schemes and their application on the platform of cloud storage.The paper analyses the latest hierarchical encryption access control schemes. To shortenparameters and increase efficiency, the paper proposes three improved hierarchicalencryption access control schemes by the strategy of Lazy and Game Theory and twooptimal ways about the three parts of hierarchical access control system on the platformof cloud storage. The main research achievement is composed by four parts.Firstly, the analysis of Jung-Wen Lo scheme is done about prime pairs, themaximum length public parameter in key generation phase, computational efficiency inkey derivation and dynamic key management phases. Combining with the strategy ofLazy-computation, the paper proposes a new hierarchical encryption access controlscheme with high efficiency.Secondly, the problem of public parameters storage is found when Jung-Wen Loscheme is used on cloud storage. An improved hierarchical encryption access controlscheme with constant size public parameter is proposed. The storage space, calculationefficiency of public parameters and the interaction information between CA and thetrusted public platform are provided. At last, the constraint security proof is providedform the new scheme to Harn-Lin scheme on key recovery model. Then, to reduce the public parameters more, the paper proposes an identityhierarchical encryption access control with constant size public parameter and analysesthe efficiency of public parameters on storage among the three schemes. At last, thesecurity of new scheme is proved form Harn-Lin scheme on key recovery model.Finally, the problem of information loss is considered when any users are off linein the dynamic key management phase. The paper analyses the efficiency of versionnumber way, and proposes two improved ways, which use symmetric encryption andidentity encryption, separately.