Narrow Results

Mandatory access control (MAC) mechanisms control which users or processes have access to which resources in a system. MAC policies are increasingly specified to facilitate managing and maintaining access control. However, the correct specification of the policies is a very challenging problem. To formally and precisely capture the security properties that MAC should adhere to, MAC models are usually written to bridge the rather wide gap in abstraction between policies and mechanisms. In this paper, we propose a general approach for property verification for MAC models. The approach defines a standardized structure for MAC models, providing for both property verification and automated generation of test cases. The approach expresses MAC models in the specification language of a model checker and expresses generic access control properties in the property language. Then the approach uses the model checker to verify the integrity, coverage, and confinement of these properties for the MAC models and finally generates test cases via combinatorial covering array for the system implementations of the models.

In order to ensure policy compliance, it is important for all stakeholders to understand the policy. One of the ways in which policies are represented in an organization is first-order logic. We propose a metric-based approach to measure understandability by measuring the structural complexity of the first-order representation of a policy. In this regard, we define a two-step approach that first calculates the complexity of an individual policy and then computes the complexity of a set of policies or a policy set. A running example of a policy set of six policies taken from the health domain is used. Finally, we evaluate the metrics using theoretical framework of Zuse. The relationship between structural complexity of a policy set and understandability is established by performing empirical validations. This was done by formulating policy sets from 23 domains.

Information flow control on the Internet is a desirable feature when it comes to content such as neo-Nazi propaganda, child pornography, or material showing extreme violence or crimes. In order to provide for a flexible control of information flow on the Internet, we present the pattern system InFO (short for: Information Flow Ontology). InFO provides a common support for different enforcing systems such as routers, proxies, or name servers by abstracting from existing as well as possible future regulation types. Thus, unlike existing solutions, InFO provides information flow control on the Internet-layer, transport-layer, as well as application-layer. In addition, InFO allows for linking the technical implementation of a flow control policy with a human-readable representation including its legal background (law) and organizational motivation (code of conduct). Besides a detailed description of the pattern system, we also provide various examples demonstrating the practical applicability of InFO. InFO has been implemented for name servers, routers, as well as application-level proxy servers. Its source code is available to the public.

In this chapter, we propose the structural model in terms of the Stair Tree model and barrier option to evaluate the fair deposit insurance premium in accordance with the constraints of the deposit insurance contracts and the consideration of bankruptcy costs. First, we show that the deposit insurance model in Brockman and Turle (2003) is a special case of our model. Second, the simulation results suggest that insurers should adopt a forbearance policy instead of a strict policy for closure regulation to avoid losses from bankruptcy costs. An appropriate deposit insurance premium can alleviate potential moral hazard problems caused by a forbearance policy. Our simulation results can be used as reference in risk management for individual banks and for the Federal Deposit Insurance Corporation (FDIC).

Scientists and policymakers alike have increasingly been interested in exploring ways to advance algorithmic fairness, recognizing not only the potential utility of algorithms in biomedical and digital health contexts but also that the unique challenges that algorithms—in a datafied culture such as the United States—pose for civil rights (including, but not limited to, privacy and nondiscrimination). In addition to the technical complexities, separation of powers issues are making the task even more daunting for policymakers—issues that might seem obscure to many scientists and technologists. While administrative agencies (such as the Federal Trade Commission) and legislators have been working to advance algorithmic fairness (in large part through comprehensive data privacy reform), recent judicial activism by the Roberts Court threaten to undermine those efforts. Scientists need to understand these legal developments so they can take appropriate action when contributing to a biomedical data ecosystem and designing, deploying, and maintaining algorithms for digital health. Here I highlight some of the recent actions taken by policymakers. I then review three recent Supreme Court cases (and foreshadow a fourth case) that illustrate the radical power grab by the Roberts Court, explaining for scientists how these drastic shifts in law will frustrate governmental approaches to algorithmic fairness and necessitate increased reliance by scientists on self-governance strategies to promote responsible and ethical practices.

Web services are becoming increasingly popular for implementing business software systems, partly due to the flexibility offered as functionality can be dynamically changed or extended by adding or replacing services. A proposed approach to speed up service discovery is to group functionally similar web services into so-called communities. However, the state-of-the-art development protocol of web service communities lacks ability to accommodate web services which do not completely satisfy the expectations of the community. This paper explains why it may be useful to have a more flexible approach where new services may be allowed into a community even if they initially appear not to fully comply with the community's expectations. A policy based negotiation approach is proposed, allowing the community master service to automatically include new services in a flexible manner. The approach is supported by an implemented tool prototype and illustrated by an example.

While Digital Libraries (DLs) are moving towards universally accessible collections of human knowledge, considerable advances are needed in DL methodologies and technologies to make this happen. Interoperability between DLs is a crucial requirement to achieve this goal. The European project, DL.org, is focused on advancing the state of the art in this area by proposing solutions, fostering best practices and shared standards, drawing on the knowledge acquired during the DELOS Network of Excellence, and harnessing the expertise of DL domain stakeholder communities. By serving this goal, DL.org is paving the way for the embedding of new research achievements into real-world systems, opening up new cross-domain research perspectives and supporting the advancement of the European Information Space for the knowledge-based economy.