Learn More
We consider the problem of deciding whether an innnite-state system (expressed as a Markov chain) satisses a correctness property with probability 1. This problem is, of course, undecidable for general innnite-state systems. We focus our attention on the model of proba-bilistic lossy channel systems consisting of nite-state processes that communicating over(More)
This paper presents a mu-calculus-based modal logic for describing properties of reactive probabilistic labeled transition systems (RPLTSs) and develops a model-checking algorithm for determining whether or not states in finite-state RPLTSs satisfy formulas in the logic. The logic is based on the distinction between (probabilis-tic) " systems " and(More)
Formal methods based on symbolic representations have been found to be very effective. In the case of infinite state systems, there has been a great deal of interest in accelerations – a technique for characterizing the result of iterating an execution sequence an arbitrary number of times, in a sound, but not necessarily complete, way. We propose the use(More)
Remotely-launched software exploits are a common way for attackers to intrude into vulnerable computer systems. As detection techniques improve, remote exploitation techniques are also evolving. Recent techniques for evasion of exploit detection include <i>polymorphism</i> (code encryption) and <i>meta-morphism</i> (code obfuscation). This paper addresses(More)
This paper investigates the use of abstract-interpretation-inspired techniques for improving the performance of procedures for determining when systems satisfy formulas in branching-time temporal logic. A framework for abstracting system descriptions is developed, and a particular method for generating abstract systems from given abstractions on system(More)
of n finite state machines, communicating with each other asynchronously using typed messages over unbounded FIFO channels, In this paper we present a data flow approach to analyzing these communicating machines for nonprogress properties (deadlock and unspecified reception). We set up flow equations to compute the set of pending messages in the queues at(More)
With software playing an increasingly important role in medical devices, regulatory agencies such as the US Food and Drug Administration need effective means for assuring that this software is safe and reliable. The FDA has been striving for a more rigorous engineering-based review strategy to provide this assurance. The use of mathematics-based techniques(More)