As a methodology for evaluating cryptographic protocols, strand spaces have the advantage of incorporating techniques developed by Millen, Meadows, Roscoe, Lowe, and others. Further investigations have shown that strand space theory can be extended and generalized in many ways. In this lecture, we present the basic definitions, motivate the fundamental theorems, and give an outline of their proofs. We will conclude the lecture by applying strand space theory to the TMN protocol. This lecture gives an introductory formulation of this concept and provides necessary and sufficient conditions for a system to satisfy noninterference.
Security is defined in terms of allowable flows of information among security domains.
We examine properties of special sets called basis elements which are generated from the interference relationship defined from the allowable flows of information. We present a decision procedure for noninterference when the system is deterministic. In this talk, I will focus on algorithmic methods for exactly computing the reachable states of hybrid systems. Current state of the art methods perform reachability computation for untimed, timed, multirate, and rectangular hybrid automata before reaching undecidability barriers. Using the very recent notion of order minimality from geometric model theory, the first class of hybrid systems with linear differential equations having a decidable reachability problem is obtained.