A privacy-preserving interdomain audit framework

Recent trends in Internet computing have led to the popularization of many forms of virtual organizations. Examples include supply chain management, grid computing, and collaborative research environments like PlanetLab. Unfortunately, when it comes to the security analysis of these systems, the whole is certainly greater than the sum of its parts. That is, local intrusion detection and audit practices are insufficient for detecting distributed attacks such as coordinated network reconnaissance, stepping-stone attacks, and violations of application-level trust constraints between security domains. A distributed process that coordinates information from each member could detect these types of violations, but privacy concerns between member organizations or safety concerns about centralizing sensitive information often restrict this level of information flow. In this paper, we propose a privacy-preserving framework for distributed audit that allows member organizations to detect distributed attacks without requiring the release of excessive private information. We discuss both the architecture and mechanisms used in our approach and comment on the performance of a prototype implementation.