An integrated firewall policy validation tool.

Security policies are increasingly being implemented by organisations. Policies are mapped to device configurations to enforce the policies. This is typically performed manually by network administrators. The development and management of these enforcement policies is a difficult and error prone task. This thesis describes the development and evaluation of an off-line firewall policy parser and validation tool. This provides the system administrator with a textual interface and the vendor specific low level languages they trust and are familiar with, but the support of an off-line compiler tool. The tool was created using the Microsoft C#.NET language, and the Microsoft Visual Studio Integrated Development Environment (IDE). This provided an object environment to create a flexible and extensible system, as well as simple Web and Windows prototyping facilities to create GUI front-end applications for testing and evaluation. A CLI was provided with the tool, for more experienced users, but it was also designed to be easily integrated into GUI based applications for non-expert users. The evaluation of the system was performed from a custom built GUI application, which can create test firewall rule sets containing synthetic rules, to supply a variety of experimental conditions, as well as record various performance metrics. The validation tool was created, based around a pragmatic outlook, with regard to the needs of the network administrator. The modularity of the design was important, due to the fast changing nature of the network device languages being processed. An object oriented approach was taken, for maximum changeability and extensibility, and a flexible tool was developed, due to the possible needs of different types users. System administrators desire, low level, CLI-based tools that they can trust, and use easily from scripting languages. Inexperienced users may prefer a more abstract, high level, GUI or Wizard that has an easier to learn process. Built around these ideas, the tool was implemented, and proved to be a usable, and complimentary addition to the many network policy-based systems currently available. The tool has a flexible design and contains comprehensive functionality. As opposed to some of the other tools which perform across multiple vendor languages, but do not implement a deep range of options for any of the languages. It compliments existing systems, such as policy compliance tools, and abstract policy analysis systems. Its validation algorithms were evaluated for both completeness, and performance. The tool was found to correctly process large firewall policies in just a few seconds. A framework for a policy-based management system, with which the tool would integrate, is also proposed. This is based around a vendor independent XML-based repository of device configurations, which could be used to bring together existing policy management and analysis systems.

A decentralized batch-based group key management potocol for mobile Internet of Thngs (DBGK).

It is anticipated that constrained devices in the Internet of Things (IoT) will often operate in groups to achieve collective monitoring or management tasks. For sensitive and mission-critical sensing tasks, securing multicast applications is therefore highly desirable. To secure group communications, several group key management protocols have been introduced. However, the majority of the proposed solutions are not adapted to the IoT and its strong processing, storage, and energy constraints. In this context, we introduce a novel decentralized and batch-based group key management protocol to secure multicast communications. Our protocol is simple and it reduces the rekeying overhead triggered by membership changes in dynamic and mobile groups and guarantees both backward and forward secrecy. To assess our protocol, we conduct a detailed analysis with respect to its communcation and storage costs. This analysis is validated through simulation to highlight energy gains. The obtained results show that our protocol outperforms its peers with respect to keying overhead and the mobility of members.