An Algebra for Integration and Analysis of Ponder2 Policies

Traditional policies often focus on access control requirement and there have been several proposals to define access control policy algebras to handle their compositions. Recently, obligations are increasingly being expressed as part of security policies. However, the compositions and interactions between these two have not yet been studied adequately. In this paper, we propose an algebra capturing both authorization and obligation policies. The algebra consists of two policy constants and six basic operations. It provides language independent mechanisms to manage policies. As a concrete example, we instantiate the algebra for the Ponder2 policy language

Ponder2: A Policy System for Autonomous Pervasive Environments

Accepted versio

Security Management System for 4G Heterogeneous Networks

There is constant demand for the development of mobile networks to meet the service requirements of users, and their development is a significant topic of research. The current fourth generation (4G) of mobile networks are expected to provide high speed connections anywhere at any time. Various existing 4G architectures such as LTE and WiMax support only wireless technologies, while an alternative architecture, Y-Comm, has been proposed to combine both existing wired and wireless networks. Y-Comm seeks to meet the main service requirements of 4G by converging the existing networks, so that the user can get better service anywhere and at any time. One of the major characteristics of Y-Comm is heterogeneity, which means that networks with different topologies work together to provide seamless communication to the end user. However, this heterogeneity leads to technical issues which may compromise quality of service, vertical handover and security. Due to the convergence characteristic of Y-Comm, security is considered more significant than in the existing LTE and WiMax networks. These security concerns have motivated this research study to propose a novel security management system. The research aims to meet the security requirements of 4G mobile networks, e.g. preventing end user devices from being used as attack tools. This requirement has not been met clearly in previous studies of Y-Comm, but this study proposes a security management system which does this. This research follows the ITU-T recommendation M.3400 dealing with security violations within Y-Comm networks. It proposes a policy-based security management system to deal with events that trigger actions in the system and uses Ponder2 to implement it. The proposed system, located in the top layer of the Y-Comm architecture, interacts with components of Y-Comm to enforce the appropriate policies. Its four main components are the Intelligent Agent, the Security Engine, the Security Policies Database and the Security Administrator. These are represented in this research as managed objects to meet design considerations such as extensibility and modifiability. This research demonstrates that the proposed system meets the security requirements of the Y-Comm environment. Its deployment is possible with managed objects built with Ponder2 for all of the components of Y-Comm, which means that the security management system is able to prevent end user devices from being used as attack tools. It can also achieve other security goals of Y-Comm networks

Security Policy Definition and Enforcement in Distributed Systems

Security in computer systems is concerned with protecting resources from unauthorized access while ensuring legitimate requests can be satisfied all the time. The recent growth of computer systems both in scale and complexity poses tremendous management challenges. Policy-based systems management is a very promising solution in this scenario. It allows the separation of the rules that govern the behavior choices of a system from the provided functionality, and can be adapted to handle a large number of system elements. In the past two decades there have been many advances in the field of policy research. Although existing solutions in centralized systems are well-established, they do not work nearly as well in distributed environments because of scalability, network partitions, and the heterogeneity of the endpoints. This dissertation contributes to this endeavor by proposing three novel techniques to address the problem of security policy definition and enforcement in large-scale distributed systems. To correctly enforce service and security requirements from users who have no intimate knowledge of the underlying systems, we introduce the first distributed policy refinement solution that translates high-level policies into low-level implementable rules, for which the syntax and semantics can be fully interpreted by individual enforcement points. Taking advantage of both the centralized and end-to-end enforcement approaches, we propose a novel policy algebra framework for policy delegation, composition and analysis. As a concrete instantiation of policy delegation enabled by the algebraic framework, we invent a novel firewall system, called ROFL (routing as the firewall layer), that implements packet filtering using the underlying routing techniques. ROFL implements a form of ubiquitous enforcement, and is able to drop malicious packets closer to their origins to save transmission bandwidth and battery power, especially for resource-limited devices in mobile ad hoc networks (MANET). The correctness and consistency of ROFL can be verified using policy algebra. It provides formalisms to address the complexity of distributed environments, increase assurance and show how to tune tradeoffs and improve security with ubiquitous enforcement. To demonstrate the effectiveness and efficiency of ROFL as a high-performance firewall mechanism, we analyze its performance quantitatively and conduct experiments in a simulated environment with two ad-hoc routing protocols. Empirical study shows that the increase in traffic for handling ROFL routing messages is more than outweighed by the savings by early drops of unwanted traffic

An interoperability framework for security policy languages

A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophySecurity policies are widely used across the IT industry in order to secure environments. Firewalls, routers, enterprise application or even operating systems like Windows and Unix are all using security policies to some extent in order to secure certain components. In order to automate enforcement of security policies, security policy languages have been introduced. Security policy languages that are classified as computer software, like many other programming languages have been revolutionised during the last decade. A number of security policy languages have been introduced in the industry in order to tackle a specific business requirements. Not to mention each of these security policy languages themselves evolved and enhanced during the last few years. Having said that, a quick research on security policy languages shows that the industry suffers from the lack of a framework for security policy languages. Such a framework would facilitate the management of security policies from an abstract point. In order to achieve that specific goal, the framework utilises an abstract security policy language that is independent of existing security policy languages yet capable of expressing policies written in those languages. Usage of interoperability framework for security policy languages as described above comes with major benefits that are categorised into two levels: short and long-term benefits. In short-term, industry and in particular multi-dimensional organisations that make use of multiple domains for different purposes would lower their security related costs by managing their security policies that are stretched across their environment and often managed locally. In the long term, usage of abstract security policy language that is independent of any existing security policy languages, gradually paves the way for standardising security policy languages. A goal that seems unreachable at this moment of time. Taking the above facts into account, the aim of this research is to introduce and develop a novel framework for security policy languages. Using such a framework would allow multi-dimensional organisations to use an abstract policy language to orchestrate all security policies from a single point, which could then be propagated across their environment. In addition, using such a framework would help security administrators to learn and use only one single, common abstract language to describe and model their environment(s)

OWL-POLAR : A Framework for Semantic Policy Representation and Reasoning

Peer reviewedPreprin

OWL-POLAR : semantic policies for agent reasoning

The original publication is available at www.springerlink.comPostprin

Policy-driven planning in coalitions - A case study

(c)IFAAMASPeer reviewedPostprin

Network operator intent : a basis for user-friendly network configuration and analysis

Two important network management activities are configuration (making the network behave in a desirable way) and analysis (querying the network’s state). A challenge common to these activities is specifying operator intent. Seemingly simple configurations such as “no network user should exceed their allocated bandwidth” or questions like “how many network devices are in the library?” are difficult to formulate in practice, e.g. they may require multiple tools (like access control lists, firewalls, databases, or accounting software) and a detailed knowledge of the network. This requires a high degree of expertise and experience, and even then, mistakes are common. An understanding of the core concepts that network operators manipulate and analyse is needed so that more effective, efficient, and user-friendly tools and processes can be created. To address this, we create a taxonomy of languages for configuring networks, and use it to evaluate three such languages to learn how operators can express their intent. We identify factors such as language features, testing, state modeling, documentation, and tool support. Then, we interview network operators to understand what they want to express. We analyse the interviews and identify nine orthogonal dimensions which frequently appear in expressions of operator intent. We use these concepts, and our taxonomy, as the basis for a language for querying both business- and network-domain data. We evaluate our language and find that it reduces the number and complexity of queries needed to answer questions about networks. We also conduct a user study, and find that our language reduces novices’ cognitive load while increasing their accuracy and efficiency. With our language, users better understand how to approach questions, can more easily express themselves, and make fewer mistakes when interpreting data. Overall, we find that operator intent can, at one extreme, be expressed directly, as primitives like flow rules, packet counters, or CLI commands, and at another extreme as human-readable statements which are automatically translated and implemented. The former gives operators precise control, but the latter may be easier to use. We also find that there is more to expressing intent than syntax and semantics as usability, redundancy, state manipulation, and ecosystems all play a role. Our findings also show the importance of incorporating business-domain concepts in network management tools. By understanding operator intent we can reduce errors, improve both human-human and human-computer communication, create more usable tools, and make network operators more effective