Privacy policies often place requirements on the purposes for which a governed entity may use personal information. For example, regulations, such as HIPAA, require that hospital employees use medical information for only certain purposes, such as treatment. Thus, using formal or automated methods for enforcing privacy policies requires a semantics of purpose requirements to determine whether an action is for a purpose or not. We provide such a semantics using a formalism based on planning. We model planning using a modified version of Markov Decision Processes, which exclude redundant actions for a formal definition of redundant. We use the model to formalize when a sequence of actions is only for or not for a purpose. This semantics enables us to provide an algorithm for automating auditing, and to describe formally and compare rigorously previous enforcement methods.
We propose an abstract model of business processes for the purpose of (i) evaluating privacy policy in light of the goals of the process and (ii) developing automated support for privacy policy compliance and audit. In our model, agents that send and receive tagged personal information are assigned organizational roles and responsibilities. We present approaches and algorithms for determining whether a business process design simultaneously achieves privacy and the goals of the organization (utility). The model also allows us to develop a notion of minimal exposure of personal information, for a given process. We investigate the problem of auditing with inexact information and develop methods to identify a set of potentially culpable individuals when privacy is breached. The audit methods draw on traditional causality concepts to reduce the effort needed to search audit logs for irresponsible actions. The protection of customer privacy is a fundamental issue in today’s corporate marketing strategies. Not surprisingly, many research efforts have proposed new privacy-aware technologies. Among them, Hippocratic databases offer mechanisms for enforcing privacy rules in database systems for inter-organizational business processes (also known as virtual organizations). This paper extends these mechanisms to allow for hierarchical purposes, distributed authorizations and minimal disclosure supporting the business processes of virtual organizations that want to offer their clients a number of ways to fulfill a service. Specifically, we use a goal-oriented approach to analyze privacy policies of the enterprises involved in a business process. On the basis of the purpose hierarchy derived through a goal refinement process, we provide algorithms for determining the minimum set of authorizations needed to achieve a service. This allows us to automatically derive access control policies for an inter-organizational business process from the collection of privacy policies associated with different participating enterprises. By using effective on-line algorithms, the derivation of such minimal information can also be done on-the-fly by the customer wishing to access a service.