Determining whether a given policy meets a site's high-level security goals has been a challenging task, due to the low-level nature and complexity of the policy language, various security requirements and the multiple policy violation patterns. In this book, we outline a systematic policy analysis and management approach that enables system administrators to easily identify and resolve various policy violations. Our approach incorporates a domain-based isolation model to address the security requirements and visualization mechanisms to provide the policy administrator with intuitive cognitive sense about the policy analysis and policy violations. Based on the domain-based isolation model and the policy visualization mechanisms, we develop a visualization-based policy analysis and management framework. We also describe our implementation of a visualization-based policy analysis and management tool that provides the functionality discussed in our framework. Also, based on our policy analysis work, a remote attestation framework is proposed and proved with efficiency and effectiveness