Information-Theoretic Modeling and Analysis of Interrupt-Related Covert Channels

Abstract. We present a formal model for analyzing the bandwidth of covert channels. The focus is on channels that exploit interrupt-driven communication, which have been shown to pose a serious threat in practical experiments. Our work builds on our earlier model [1], which we used to compare the effectiveness of different countermeasures against such channels. The main novel contribution of this article is an approach to exploiting detailed knowledge about a given chan-nel in order to make the bandwidth analysis more precise.