Policy Compliance in Collaborative Systems

Abstract

When collaborating agents share sensitive information to achieve a common goal it would be helpful to them to decide whether doing so will lead to an unwanted release of confidential data. These decisions are based on which other agents are involved, what those agents can do in the given context, and the individual confidentiality preferences of each agent. In this paper we consider a model of collaboration in which each agent has an explicit confidentiality policy. We offer three ways to interpret policy compliance (system compliance, plan compliance and weak plan compliance) corresponding to different levels of trust among the agents. We show it is EXPSPACE-complete to determine whether a given system is compliant and whether the agents can collaboratively reach a given common goal. On the other hand, we show it is undecidable to determine whether a given system has either a compliant plan or a weakly compliant plan leading to a common goal. The undecidability results are, in part, a consequence of the flexibility of the model, which allows interpretations of policy compliance that depend on current configurations.

Collaborative Planning with Confidentiality

“…This allows us to show that the collaborative planning problems are both decidable. In fact, in other work [25] we lift the well-balanced restriction and show that the problem with system compliance is still decidable, but the version with plan compliance becomes undecidable.…”

“…This is an important difference from MSR [12] which has been shown to have correspondences with linear logic [9,46]. We actually use this connection to affine logic rather explicitly in other work [25,44] which helps to illuminate some of the differences from MSR and its connection to linear logic. Finally, it can be desirable to have such a logical foundation because we are often able to gain new insight by thinking in terms of a well established formalism.…”

“…In particular, if we put no restrictions on the form of the actions, then we could grow the global state to an arbitrarily large size. The general case for goal reachability (where there are no confidentiality policies) has the same complexity as the coverability problem for Petri nets [15,25,31,44]. Although this is decidable [35], it overestimates the complexity of the typical case.…”

“…In [25,44] we demonstrated formal translations between the coverability problem for Petri nets and the reachability problem for local state transition systems. Under our translation, well-balanced local state transition systems do not seem to correspond exactly to any of the various types of Petri nets described in [23].…”

Towards HIPAA-compliant healthcare systems

“…We have witnessed several organizations such as hospitals, financial institutions, and government sectors have been suffering from information leakage and policy violations due to the lack of systematic mechanisms for policy compliance and enforcement [5,11,23]. For example, Health Insurance Portability and Accountability Act (HIPAA), the Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page.…”