An Empirical Bandwidth Analysis of Interrupt-Related Covert Channels

2. Background

Covert channels. There are multiple definitions of covert channels (Gligor, 1993). Lampson (1973) defines covert channels to be communication channels that are neither designed nor intended to transfer information. Huskamp (1978) defines covert channels as channels that “are the result of resource allocation policies and resource management implementation”. This article takes a definition with an explicit notion of processes as a basis: a covert channel is “a communication channel that allows a process to transfer information in a manner that violates the system’s security policy” (Gligor, 1993). In contrast to side channels, covert channels consider a sender that deliberately participates in the communication.