A secure kernelized architecture for multilevel object-oriented databases

The authors present a secure kernelized architecture for multilevel object-oriented database management systems. The architecture is based on the notion of a message filter. It builds upon the typical architecture of current object-oriented database management systems. Since the operations mediated by the message filter are arbitrarily complex operations (as opposed to primitive reads and writes), a secure message filter requires careful attention to potential timing covert channels. Although the overall computation is logically a sequential one, to be secure one must actually execute pieces of the computation concurrently. This raises a synchronization problem for which they give a secure multiversion protocol. The fundamental problem solved is how to securely and correctly `write up´ in terms of abstract operations