Based on the analysis of typical binary and dynamic binary search anti-collision algorithm in RFID system, this article proposes a fast and efficient anti-collision algorithm, that is, conduct dynamic packet on tags and adjust query instruction. The performance analysis and experiments show: this algorithm greatly reduces the tag identification time, and increases the identification efficiency of RFID system. At the same time, it reduces information exposure of tags when reader communicates with tags, and effectively decreases the collision probability of tags.

No abstract

In a dynamic coalition environment, organizations should be able to exercise their own local fine-grained access control policies while sharing resources with external entities. At the same time, the status of XML as a standard for storing and exchanging data in Internet and XML documents is becoming a de facto standard for storing and exchanging information. So, access control of XML documents is a key in dynamic coalition environment. In this paper, we propose an approach that exploits the semantics associated with subject and information in XML documents to facilitate automatic access control policies while resource sharing occurs among coalition members. Our approach relies on identifying the necessary attributes required by users to gain access to specific XML documents information. Specifically, it consists of extracting user attribute sets that semantically mach with the attributes of the information in XML documents. This relies on a closer examination of why a user is assigned a specific role.

No abstract

A multi-polices access control model is proposed, with the model, access control based on policy regulation and XML based policy description is given. At the same time, We use the XSD(XML Schema Definition) to describe the content and the structure of the xml documents, and check the validity of the xml documents. Based on the description of the access control, an application system is realized we construct the runtime platform and choose some access control polices to test our system. The result is well.