摘要 |
In a method of controlling access in a data processing system, firstly a set of attributes is defined for targets that may be accessed and for accessors that may access the targets. A set of access security classes is then defined in terms of these attributes or other classes. Each class has a set of allowable operations associated with it. Each target is assigned a classification comprising one of the classes and a set of allowed operations. Each accessor is assigned an authority consisting of one of the classes and a set of allowed operations. An accessor is allowed to access a target only if there is a common sub-class contained in both the accessor's authority and in the target's classification, 21 and if the required operation is defined for that subclass and appears in both the accessor's authority and in the target's classification, 22. <IMAGE> |