Biblio

Firewalls and Demilitarized Zones (DMZs) are two mechanisms that have been widely employed to secure enterprise networks. Despite this, their security effectiveness has not been systematically quantified. In this paper, we make a first step towards filling this void by presenting a representational framework for investigating their security effectiveness in protecting enterprise networks. Through simulation experiments, we draw useful insights into the security effectiveness of firewalls and DMZs. To the best of our knowledge, these insights were not reported in the literature until now.

Complex safety-critical devices require dependable communication. Dependability includes confidentiality and integrity as much as safety. Encrypting gateways with demilitarized zones, Multiple Independent Levels of Security architectures and the infamous Air Gap are diverse integration patterns for safety-critical infrastructure. Though resource restricted embedded safety devices still lack simple, certifiable, and efficient cryptography implementations. Following the recommended formal methods approach for safety-critical devices, we have implemented proven cryptography algorithms in the qualified model based language Scade as the Safety Leveraged Implementation of Data Encryption (SLIDE) library. Optimization for the synchronous dataflow language is discussed in the paper. The implementation for public-key based encryption and authentication is evaluated for real-world performance. The feasibility is shown by execution time benchmarks on an industrial safety microcontroller platform running a train control safety application.