Task-Role Based Access Control For Embedded Real-Time Database Systems

With the extensive applications of embedded systems and the ever-growing popularity of embedded real-time operating systems, the data management under embedded environment has become one of the important problems in the system. Embedded real-time database management system (ERTDBMS) can provide efficient support for this problem. With the internet-oriented and open development trend of embedded systems, security control in the system is also one of the challenges which has to be faced.ARTs-EDB is an embedded active real-time database management system, which is developed independently and possesses proprietary intellectual property rights. The access control approach in ARTs-EDB is very different from the traditional database. In traditional database, it denies or allows the access to objects through checking permissions owned by subjects, not considering the timing constraints of transactions or data. The traditional needs absolute security. The data and transactions in ERTDBS both have explicit timing constraints. When to implement access control in ERTDBS, the requirements of real-time and security must be considered simultaneously. That means not only providing secure access to data but also minimizing the missing ratio of transactions'deadlines.Role-based access control (RBAC) model has a good adaptability. An access control model suited for ERTDBS was presented through appropriate clip and extension on RBAC. This model executes access control in a task-oriented way, and the extention of features on roles makes it perform access control with some real-time characteristics. Furthermore, an effective execution model was built for the access control model based on the abstraction of security management activities in ERTDBS. The mechanism of active rules were employed for executing access control.The implementation of access control influences the execution of transactions inevitably, including the admission control, schedule management, concurrency control and commit management of transactions. The experimental results on ARTs-EDB indicated that the access control mode mentioned above can provide efficient security control for the system and influence the execution of transactions slightly.