Multi-constraint Security Policies for Delegated Firewall Administration

International audienceThis work presents a new policy based security framework that is able handle simultaneously and coherently mandatory, discretionary and security property policies. One important aspect of the proposed framework is that each dimension of the security policies can be managed independently, allowing people playing different roles in an organization to define security policies without violating a global security goal. The framework creates an abstract layer that permits to define security policies independently of how they will be enforced. For example, the mandatory and security property polices could be assigned to the risk management staff while the discretionary policies could be delegated among the several departments in the organization

Multi-constraint security policies for delegated firewall administration

International audienceThis work presents a new approach to policy representation of network security. It introduces a high-level language, where the security policies can be expressed by three policy models: mandatory, discretionary and security property. The proposed framework is capable of handling all three dimensions, being capable of generating the permissions from an abstract representation that is independent of how they are enforced, without violating the requirements of high-level security. Each dimension can be defined by people with different roles; for example, rules of the mandatory model and of the security property model could be attributed to the personnel of risk management, while rules of the discretionary model can be delegated among the network administrators in various departments of the organization. This work also presents a mechanism to represent the features implemented by different firewall models and a mechanism for translating the abstract representation in the scripts to configure the firewalls. A formal specification of the policy model validates the refinement algorithm and a study of scalability is presented to demonstrate how the algorithm behaves in large networks

Stakeholder security analysis - a new approach to security design with example application

Stakeholder security analysis (SSA) is a rigorous approach to analysing and designing systems from the point of view of cybersecurity which is defined and applied in this dissertation. SSA starts by identifying the objectives of the stakeholders, and then seeks to find rules which can be enforced to ensure that these objectives are met. It is shown by several detailed examples in this dissertation, and proved theoretically, by means of Hilbert's thesis, that first order logic is able to express any mathematical model and correctly explains the concept of logical proof; and that stakeholder security analysis can be used systematically to design secure systems. The relationship between the different cybersecurity rules is illustrated by means of inference graphs, which show how the rules which are enforced ensure that the objectives are met. Chapter 1 provides an introduction, background, and presents outcomes of research significance. Chapter 2 reviews the relevant literature on the philosophy of security design that is applied to the application areas of web security, network security, and emergency networks. Chapter 3 defines stakeholder security analysis, including its theoretical justification, by means of Hilbert's thesis, and explains the use of inference graphs, which were developed as part of this research. Service protection rules are defined, in this chapter, as rules which, without appearing to define or ensure security, are nevertheless essential because they ensure that a service fulfils its objectives. Examples of these are provided in subsequent chapters, where it becomes clear that unless this type of rule is included, the system being designed is logically incomplete. In Chapter 4, stakeholder security analysis is applied to web services, and, in particular, to the Netml system for network analysis, design and simulation. It is used to design and prove the security of certain aspects of the system. In Chapter 5, the design of network filters and firewalls is considered, together with the security implications of virtual private networks. The use of simulation for security analysis of networks is explored practically, and the capability and limitations of simulation as a tool for security analysis of networks are investigated, using stakeholder security analysis as a rigorous framework that underpins all the proposed methods. It is shown that simulation can be rigorously used to prove the consistency of policies, and the sense in which simulation is able to prove the validity of cybersecurity is identified. In Chapter 6, the stakeholder security analysis is applied to emergency networks. The purpose of emergency networks is to save lives. The possibility of misuse and attacks upon an emergency network is also considered. A key consideration in the management of power for the devices which form the network. Five experiments concerned with the management of battery life to save lives in emergency situations are presented. Conclusions are presented in Chapter 7