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Existing key distribution scheme based on key derivation has security default in cloud scenarios. The scheme distributes decryption keys to users through tags stored on cloud server. If the tag is destroyed by cloud server intentionally or unintentionally, the key distribution is destroyed too. Besides the above case, if all related tags are stored on client operated by user, the storage burden is...
While outsourcing data to cloud, security and efficiency issues should be taken into account. However, it is very challenging to design a secure and efficient mechanism supporting authorization updates. In this paper, we aim to provide a mechanism supporting authorization updates which only incurs a lightweight cost of authorization updates and meanwhile supports a high level of security. This mechanism...
According to the multiple security levels requirement of privacy cloud, we firstly propose a mandatory access control model for privacy cloud. Secondly, we illustrate the function of each module in the model. Thirdly, present the implementation model based on the data flow technology corresponding to each module. Fourthly, formally descript our models. Finally, verification results show that our mandatory...
As a more flexible and effective access control mechanism in databases, fine-grained access control (FGAC) has drawn considerable attention from industrial and research community. While providing more effective protection for databases, FGAC also incurs new loopholes for attacks. When FGAC policies are defined inconsistently, performing UPDATE/DELETE operations might cause information inference, called...
The fine-grained access control approaches in DBMSs should satisfy soundness property which requires the answer of a query returned by the approach under the control of fine-grained access control is consistent with the answer when there is no fine-grained access control. However, existing techniques cannot guarantee soundness property for all SQL queries. Therefore, for an approach, there is a practical...
The fine-grained access control (FGAC) is important to Web applications. However, it can be circumvented by indirect access such as inferring sensitive data from insensitive data. In the previous FGAC studies, the inference information leakage is not well controlled. In addition, the soundness property, which requires that the results of a query under the FGAC should be the subset of the results of...
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