An information flow tool for Gypsy

Previously (J. McHugh, 1984), we outlined an information flow tool for the Gypsy language (D. Good et al., 1978) that could be used to support covert channel analysis. The proposed tool offered substantial advantages over existing tools in flexibility and promised to be useful for a variety of analyses. Two versions of the tool were subsequently built and used for a variety of MLS and other projects. The paper draws on the original, adding motivational and explanatory material and adds descriptions of the subsequent tools. It also illustrates a novel use of one of the tools in developing an architecture for a MLS windowing system.