Secure multilevel object oriented database management system

摘要

A secure multilevel object oriented database management system which maintains data confidentiality and optimizes data integrity. All requests for database operations are mediated through an access validation monitor (AVM). The AVM is responsible for performing the following duties: applying mandatory and discretionary access control rules for each request it services to ensure the request is allowable; constructing views of multilevel objects ensuring that the clearance level of the subject making the request dominates the classification of the data being requested; managing data update requests so as to allow polyinstantiation only upon receiving explicit requests from the subject, the explicit request being accomplished through an update to the associated semantic vector (Semantic vectors are employed to maintain data integrity); detecting erroneous polyinstantiation attempts and flagging such errors to the requesting subject; and managing the creation of new multilevel objects, and enforces entity integrity constraints. The AVM constructs the requesting subject's view of a multilevel object at a particular security level by computing a value for each property of the object. Each property value of the object if determined by inspecting the object's semantic vector. The semantic vector indicates, for each property of a multilevel object and at every populated level of said object, whether the property's value is dynamic (i.e., derived from an instantiation stored at the nearest populated dominated sensitivity level of the object where the semantic vector mark such property static).