Security Assurance for the Attribute-Based Access Control Systems

摘要

Recent operating systems govern a composition of information resources, security providing components, and interactions between them. Complexity of security and variety of its control settings takes us to a problem of security assurance. IT-security-related standards force us to prove safety of the system configurations. Searching for vulnerability in the system configuration plays a central role in information protection and intrusion prevention, for an undetected defect may be exploited to compromise every confidential data. However, so far none systematic way has been proposed to detect configuration vulnerabilities besides checking whether the fixed characteristics (file versions, updates, permissions etc) meet the security templates. In this paper, we suggest and discuss a new technique of security assurance applicable to the attribute-based access control. We propose to summarize all access factors that take part in the access control and convert them all to a Set of Available Permissions (SAP), i.e. the access rights that user really obtains in the system. SAP calculation supplies us with knowledge on exact set of available access rights and those access factors that break the due security restrictions. On the sample of MS Windows we demonstrate a formal verification procedure that solves the security assurance problem pointed above - using it we can answer whether a given system configuration fulfills the security requirements. An advantage of our mechanism is that it can be realized as automatic procedure for every kind of systems and security rules.