This article is from the Computer Security Evaluation FAQ, by Trusted Product Evaluation Program TPEP@dockmaster.ncsc.mil.
The Trusted Database Interpretation (TDI) of the TCSEC is
similar to the Trusted Network Interpretation (TNI) in that it
decomposes a system into independently evaluatable components.
It differs from the TNI in that the paradigm for this
decomposition is the evaluation of an application (e.g.,
database) running on an already evaluated system. The Trusted
Product Evaluation Program (TPEP) has to date only evaluated
databases using this interpretation. In principle arbitrary
trusted applications could be evaluated. It is available at