US Patent 7552328 Security attributes of nodes in trusted computing systems

A system and method for resolving a rule conflict within a security policy applied to a trusted computing platform, wherein the fileset to which each of the conflicting rules v and s refers (or “scope”) is determined (step 10). It is then determined (at step 12) if the scope of one of the rules s is a complete subset of the scope of rule r. If so, rule s is applied to the accessed file f (at step 14). If not, the conflict is resolved in another way, for example, by determining the most restrictive of rules r and s (at step 16) and applying the result accordingly (step 18).