Kurt Rohloff

Learn More
In this paper we discuss the use of the MapReduce software framework to address the challenge of constructing high-performance, massively-scalable distributed systems. We discuss several design considerations associated with constructing complex distributed systems using the MapReduce software framework, including the difficulty of scalably building(More)
Graph data processing is an emerging application area for cloud computing because there are few other information infrastructures that cost-effectively permit scalable graph data processing. We present a scalable cloud-based approach to process queries on graph data utilizing the MapReduce model. We call this approach the Clause-Iteration approach. We(More)
This paper discusses modeling and simulation issues associated with the stochastic behavior of a special type of a computer worm called a random constant scanning (RCS) worm. Although these worms propagate by randomly scanning network addresses to find hosts that are susceptible to infection, traditional RCS worm models are fundamentally deterministic. A(More)
In this paper we investigate computational issues associated with the supervision of concurrent processes modeled as modular discrete-event systems. Here, modular discrete-event systems are sets of deterministic finite-state automata whose interaction is modeled by the parallel composition operation. Even with such a simple model process model, we show that(More)
This paper presents a comparison of performance of various triplestore technologies currently in either production release or beta test. Our comparison of triple-store technologies is biased toward a deployment scenario where the triple-store needs to load data and respond to queries over a very large knowledge base (on the order of hundreds of millions of(More)
Practical Fully Homomorphic Encryption (FHE) would be a game-changing technology to enable secure, general computation on encrypted data, e.g., on untrusted off-site hardware. Recent theoretical breakthroughs demonstrated the existence of Fully Homomorphic Encryption schemes [1,4]. However, FHE remains impractical because current implementations are many(More)
This paper discusses the problem of selecting a set of sensors of minimum cost that can be used for the synthesis of a supervisory controller. It is shown how this sensor selection problem is related to a type of directed graph st-cut problem that has not been previously discussed in the literature. Approximation algorithms to solve the sensor selection(More)
In this paper we report on our work to design, implement and evaluate a Fully Homomorphic Encryption (FHE) scheme. Our FHE scheme is an NTRU-like cryptosystem, with additional support for efficient key switching and modulus reduction operations to reduce the frequency of bootstrapping operations. Ciphertexts in our scheme are represented as matrices of(More)
This paper explore issues related to the control and verification of similar module systems in the discrete-event systems framework. Similar module systems are distributed systems comprised of subsystem modules that exhibit isomorphic local behavior coordinated on global event occurrences. When given a global model of these systems, it is shown how to(More)