A Graph-based Language for Specifying Security Policies

A security policy states the acceptable actions of an information system, as the actions bear on security. There is a pressing need for organizations to declare their security policies, even informal statements would be better than the current practice. But, formal policy statements are preferable to support (1) reasoning about policies, e.g., for consistency and completeness, (2) automated enforcement of the policy, and (3) other formal operations on policies, e.g., the composition of policies. We present LaSCO, the Language for Security Constraints on Objects, in which a policy and a system description are independently specified. LaSCO policies are specified as expressions in a quantifier-free logic, but also, to provide visualization, as directed graphs. Formal semantics have been defined. LaSCO can be used for policy requirements that conform to its very general object-based system model. The implementation of LaSCO is in Java, and automatically generates wrappers to check Java program executions with respect to a policy.