"As adversaries develop Information Warfare capabilities, the threat of information system subversion presents a significant risk. System subversion will be defined and characterized as a warfare tool. Through recent security incidents, it is shown that means, motive, and opportunity exist for subversion, that this threat is real, and that it represents a significant vulnerability. Mitigation of the subversion threat touches the most fundamental aspect of the security problem: proving the absence of a malicious artifice. A constructive system engineering technique to mitigate the subversion threat is identified."
Defense Technical Information Center (DTIC): http://www.dtic.mil/dtic/