Certification of programs for secure information flow

ertification mechanism for verifying the secure flow of information through a program. Because it exploits the properties of a lattice structure among security classes, the procedure is sufficiently simple that it can easily be included in the analysis phase of most existing compilers. Appropriate semantics are presented and proved correct. An important application is the confinement problem: The mechanism can prove that a program cannot cause supposedly nonconfidential results to depend on confidential input data.