Manton M. Matthews

Hamiltonian results in K1,3-free graphs

There have been a number of results dealing with Hamiltonian properties in powers of graphs. In this paper we show that the square and the total graph of a K1,3-free graph are vertex pancyclic. We then discuss some of the relationships between connectivity and Hamiltonian properties in K1,3-free graphs.

Security issues in privacy and key management protocols of IEEE 802.16

Without physical boundaries, a wireless network faces many more security threats than a wired network does. Therefore, in the IEEE 802.16 standard a security sublayer is specified in the MAC layer to address the privacy issues across the fixed Broadband Wireless Access (BWA). Several articles have been published to address the flaws in IEEE 802.16 security after the IEEE standard 802.16-2001 was released. However, the IEEE standard 802.16-2004 revision does not settle all the discovered problems and additional flaws remain. This paper gives an overview of the IEEE 802.16 standard, focusing on the MAC layer and especially the security sublayer. We analyze the security flaws in the standard as well as in related works, and illustrate possible attacks to the authentication and key management protocols. Possible solutions are also proposed to prevent these attacks. Finally, we propose a security handover protocol that should be supported in the future 802.16e for mobility.

Longest paths and cycles in K1,3-free graphs

In this article we show that the standard results concerning longest paths and cycles in graphs can be improved for K1,3-free graphs. We obtain as a consequence of these results conditions for the existence of a hamiltonian path and cycle in K1,3-free graphs.

Chinese remainder theorem based group key management

In this paper, we present two new centralized group key management protocols based on the Chinese Remainder Theorem (CRT). By shifting more computing load onto the key server we optimize the number of re-key broadcast messages, user-side key computation, and number of key storages. The first protocol is the base Chinese Remaindering Group Key (CRGK) protocol, which with a group of n users requires the key server to do O(n) XORs, additions, multiplications, and Extended Euclidean Algorithm computations and broadcast 1 re-key message; each individual user is required to do only 1 modulo arithmetic and 1 XOR operation for each group key update. The second protocol is the Fast Chinese Remaindering Group Key (FCRGK) protocol, which only requires the key server to do O(n) XORs, additions, and multiplications most of the times with no change to the number of re-key messages and user computation per group key update. For both protocols each user only needs to store 2 keys all the time. One special attraction for our FCRGK protocol is that it allows most of the re-keying computation to be done preemptively, which means when a user-join or user-leave event happens the response time for the key server to send out the new group key can be very short.

Modeling and analysis of IEEE 802.16 PKM Protocols using CasperFDR

IEEE 802.16 is the standard for broadband wireless access. The security sublayer is provided within IEEE 802.16 MAC layer for privacy and access control, in which the Privacy and Key Management (PKM) protocols are specified. This paper models the PKM protocols using Casper and analyzes the CSP output with FDR, which are formal analysis tools based on the model checker. Later versions of PKM protocols are also modeled and analyzed. Attacks are found in each version and the results are discussed.

USCSH: An Active Intelligent Assistance System

This paper describes the knowledge sources and methods of knowledge acquisition for USCSH (University of South Carolina SHell). USCSH is an active intelligent assistance system for Unix. The system operates in two modes, the active mode and the intelligent mode. In the active mode USCSH monitors the users interactions with the system, and at appropriate times makes suggestions on how the user may better utilize the system to perform tasks. In the intelligent mode the system accepts questions in natural language and responds to them, taking into consideration the ability of the user and the context of the question.

A Dual Authentication Protocol for IEEE 802.11 Wireless LANs

In this paper, we first identify a vulnerability of IEEE 802.11 wireless LANs in which a compromised access point can still authenticate itself to a wireless station and gain control over the connection, and show that the current IEEE 802.11i standard does not address this problem. We then propose a new protocol that can counter this attack by providing dual authentication for both a wireless station and its corresponding access point at connection setup time using the authentication server. We also consider roaming situations and present a roaming authentication protocol. Finally, we show that our protocol is in conformance with the requirements of the IEEE 802.11i standard, and show that it performs no worse with respect to communication time than IEEE 802.11i using a prototype implementation of each protocol

Efficient and Secure Multicast in WirelessMAN

Multicast delivery of data is a powerful mechanism that has strong potential in next generation networks. The increased efficiency over unicast is a definite advantage, but the use of multicast poses many security risks. Effectively adding security measures to a multicast service is an intriguing problem, especially when the service is deployed in a wireless setting. Next generation IEEE 802.16 standard WirelessMAN networks are a perfect example of this problem, and the latest draft specification of the standard includes a secure protocol solution called multicast and broadcast rekeying algorithm (MBRA). In this paper, we expose the security problems of MBRA, including non-scalability and omission of backward and forward secrecy, and propose a new approach, ELAPSE, to address these problems. We analyze the security property of ELAPSE and use Qualnet simulations to show its efficiency

Information extraction from helicopter maintenance records as a springboard for the future of maintenance text analysis

This paper introduces a novel application of information extraction techniques to extract data from helicopter maintenance records to populate a database. The goals of the research are to preprocess the text-based data for further use in data mining efforts and to develop a system to provide a rough analysis of generic maintenance records to facilitate in the development of training corpora for use in machine-learning for more refined information extraction system design. The Natural Language Toolkit was used to implement partial parsing of text by way of hierarchical chunking of the text. The system was targeted towards inspection descriptions and succeeded in extracting the inspection code, description of the part/action, and date/time information with 80.7% recall and 89.9% precision.

Extending Description Logic for Reasoning about Ontology Evolution

Ontologies play a key role in achieving global automatic information integration and sharing on the Semantic Web. They allow intelligent applications to exchange information through a shared and formal conceptualization of an application domain. Understanding ontology evolution can help both ontology developers and users evaluating the potential consequences of ontology changes and act accordingly. Our contribution is proposing a temporal paradigm for ontology evolution and extending Description Logic with Temporal Logic operators to formally characterize and reason about ontology evolution. We investigate related reasoning problems and algorithm.