Auto-delegation of access control towards ubiquitous computing: A decision theory approach

Delegation is required to access the critical information when an authorized user is unavailable. It provides flexibility to access control. Different mechanisms are introduced for delegation in previous work, but some of them require the user to be present while performing delegation. To overcome such explicit delegation, auto-delegation is introduced. The decision theory based auto-delegation (DTA-d) is one of the auto-delegation mechanisms, which perform the auto-delegation when an authorized user is unavailable in UbiComp. The DTA-d scheme is presented in the earlier work; it helps to choose one of the subjects as a delegatee among the available subjects. The main contribution of this paper is the mathematical model for the DTA-d framework. It is presented using the decision theory, which helps to make a decision when a number of alternatives are available. Further, Capability Based Access Control (CBAC) is introduced in the paper to perform access control. The SHA-1 algorithm is used for the secure handover of capability to the delegatee. The proof of concept is also presented to validate the performance of the proposed scheme. It shows that the decision theory approach for auto-delegation is scalable, which is need of ubiquitous computing.