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Abstract

Ensuring safety in avionics has mostly been achieved through a complete separation between avionics software and open-world software, in order to avoid any interaction that could corrupt critical on-board systems. However, new aircraft generations need more interaction with off-board systems to offer extended services. The extent to which such interactions can be securely supported requires an in-depth characterization, analysis and control of potentially dangerous information flows. In this paper, we consider the safety aspect of such systems and detail the different viewpoints that justify the level of confidence that can placed on a system component.

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Abstract

The chapter proposes a new access control framework for Inter-Organizational Web Services: PolyOrBAC, extending OrBAC (Organization-Based Access Control Model) to specify rules for intra- as well as inter-organization access control and enforcing these rules by applying access control mechanisms dedicated to Web Services; it is also proposes a runtime model checker for the interactions between collaborating organizations, to verify their compliance with previously signed contracts.

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Testing network-based security tools such as Intrusion Detection and Prevention Systems (IDS/IPS) differs from testing ordinary network tools (e.g., routers and switches). Basically, in addition to the parameters (such as bandwidth utilization, routing information and packets timing) that are important for network tools, security tools are more sensitive to issues like traffic composition, contents, and sessionlevel parameters. Generating a realistic synthetic traffic that keeps all the characteristics of the real traffic has proved to be difficult. For this reason, security testers often use real traffic traces in their test or evaluation. However, the available traces are often limited in number or size. Therefore, it is necessary to merge and manipulate traces to create a test environment that would be representative of the operational environment, and to inject attacks into the traffic. A variety of tools for recording, replaying as well as forging packets can be obtained easily, but there exist very few tools for manipulating traces so as to modify the traffic composition from the networking viewpoint. Among them, surprisingly there is no tool for manipulating traces without destructing their security-relevant characteristics. In this paper, we present a brief survey for trace manipulation and packet forging tools. Then we determine the requirements of tools for manipulating traces and injecting attacks while keeping their original characteristics. Finally, we present the architecture, and the implementation of our tool intended to fill this lack in security testing tools.

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Nowadays, more and more information systems are connected to the Internet and offer Web interfaces to the general public or to a restricted set of users. Such openness makes them likely targets for intruders, and conventional protection techniques have been shown insufficient to prevent all intrusions in such open systems. This paper proposes a generic architecture to implement intrusion-tolerant Web servers. This architecture is based on redundancy and diversification principles, in order to increase the system resilience to attacks: usually, an attack targets a particular software, running on a particular platform, and fails on others. The architecture is composed of redundant proxies that mediate client requests to a redundant bank of diversified COTSfootnote{Commercial Off The Shelf.} application servers. The redundancy is deployed here to increase system availability and integrity. To improve performance, adaptive redundancy is applied: the redundancy level is selected according to the current alert level. The architecture can be used for static servers, i.e., for Web distribution of stable information (updated off-line), as well as for fully dynamic systems where information updates are executed immediately on an on-line database. The feasibility of this architecture has been demonstrated by implementing an example of a travel agency Web server.

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