A Note on the Denial-of-Service Problem

A simple and general definition of denial of service in operating systems is presented herein. It is argued that no current protection mechanism nor model resolves this problem in any demonstrable way. A set of examples from known systems is presented in order to delimit the scope of the problem. The notion of interuser dependency is introduced and identified as the common cause for all problem instances. Necessary end sufficient conditions for solutions are stated and justified informally. The relative complexity of undesirable (and unspecified) interuser dependencies is also discussed.