Association for Computing Machinery
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.