A Service Dependency Modeling Framework for Policy-Based Response Enforcement

The use of dynamic access control policies for threat response adapts local response decisions to high level system constraints. However, security policies are often carefully tightened during system design-time, and the large number of service dependencies in a system architecture makes their dynamic adaptation difficult. The enforcement of a single response rule requires performing multiple configuration changes on multiple services. This paper formally describes a Service Dependency Framework (SDF) in order to assist the response process in selecting the policy enforcement points (PEPs) capable of applying a dynamic response rule. It automatically derives elementary access rules from the generic access control, either allowed or denied by the dynamic response policy, so they can be locally managed by local PEPs. SDF introduces a requires/provides model of service dependencies. It models the service architecture in a modular way, and thus provides both extensibility and reusability of model components. SDF is defined using the Architecture Analysis and Design Language, which provides formal concepts for modeling system architect tires. This paper presents a systematic treatment of the dependency model which aims to apply policy rules while minimizing configuration changes and reducing resource consumption.