Donal O'Mahony

Abstract: In this paper we present a survey of secure ad hoc routing protocols for mobile wireless networks. A mobile ad hoc network is a collection of nodes that is connected through a wireless medium forming rapidly changing topologies. The widely accepted existing routing protocols designed to accommodate the needs of such self-organized networks do not address possible threats aiming at the disruption of the protocol itself. The assumption of a trusted environment is not one that can be realistically expected; hence several efforts have been made towards the design of a secure and robust routing protocol for ad hoc networks. We briefly present the most popular protocols that follow the table-driven and the source-initiated on-demand approaches. Based on this discussion we then formulate the threat model for ad hoc routing and present several specific attacks that can target the operation of a protocol. In order to analyze the proposed secure ad hoc routing protocols in a structured way we have classified them into five categories; solutions based on asymmetric cryptography, solutions based on symmetric cryptography, hybrid solutions, reputation-based solutions and a category of add-on mechanisms that satisfy specific security requirements. A comparison between these solutions can provide the basis for future research in this rapidly evolving area.

Abstract: From the Publisher: As the Internet continues to transform commerce as we know it, the method of payment is one component that's critical to successfully conducting business across a network. Electronic Payment Systems offers the first comprehensive, up-to-date survey of the major payment schemes currently available — from a technical user perspective. Requiring only a basic familiarity with computing and networking, the book covers numerous Internet payment systems, including E-cash, SET (secure electronic transactions), FSTC electronic check project, and Millicent. It also identifies the properties unique to the various payment schemes, provides a working knowledge of the necessary cryptography, and explains the protocols involved. In eight concisely written chapters, you acquire the background you need to fully understand how each payment system works. If you deal with payment systems and financial software on a daily basis, this book does the homework for you. It saves you time by gathering and presenting timely information on today's most influential Internet payment systems — and helps you understand the key criteria for evaluating and selecting a system that's efficient, effective, and secure. This new book is a valuable resource for technical professionals in banking/financial services, the software industry, and sales organizations, as well as for users of Electronic Commerce systems. It addresses a wide range of needs by providing timely details that help you determine the state of the market, keep apprised of new developments, adopt the most appropriate systems, develop software, and sell goods across the Internet.

Abstract: Overlay networks create a structured virtual topology above the basic transport protocol level that facilitates deterministic search and guarantees convergence. Overlay networks are evolving into a critical component for self-organizing systems. Here we outline the differences between flooding-style and overlay networks, and offer specific examples of how researchers are applying the latter to problems requiring high-speed, self-organizing network topologies.

Abstract: Preface. Motivation for Electronic Payment. Characteristics of Current Payment Systems - Cash Payments. Payment Through Banks. Using Payment Cards. Consumer Preferences in Payment Systems. Regulatory Framework. Cryptographic Techniques - Encryption and Decryption. Symmetric Encryption. AES Message Digesting or Hashing. Kerberos. Asymmetric or Public Key Encryption. Digital Signatures and Enveloping. RSA. Elliptic Curve Cryptography (ECC). Public Key Infrastructure (PKI) Transport of Security Information. Dual Signatures. Nonces. Blind Signatures. Chip Cards/Smart Cards. Summary. Credit Card Based Systems - Mail order/Telephone Order (MOTO) Transactions. Un-Secured Network Payments. Credit Card Aggregation. The Secure Socket Layer (SSL). i-Key Protocol (iKP). Secure Electronic Transactions (SET). Server Side Wallets. Account Transfers and Electronic Checks - Payment Transfer between Centralized Accounts. FSTC Electronic Check Project. NetBill. NetCheque. Summary. Electronic Cash Payment Systems - Ecash. Project CAFE. NetCash. CyberCoin. Stored Value Card Schemes. Remarks. Micropayment Systems - Millicent. Subscrip. PayWord. iKP Micropayment Protocol. X Hash Chain Trees. Micromint. Probability-Based Micropayments. Jalda. IBM Micropayments ( Mini-Pay). Banner Advertising. Micropayments Summary and Analysis. Mobile Commerce - What is M-Commerce. Billing through Mobile Operator. Mobile Payment Systems. Mobile Commerce Forums. M-Commerce Efforts for Existing Electronic Payment Systems. Payment Systems - Prospects for the Future.

Abstract: The past few years have witnessed an explosive growth in the use of wireless mobile handheld devices as the enabling technology for accessing Internet-based services, as well as for personal communication needs in ad hoc networking environments. Most studies indicate that it is impossible to utilize strong cryptographic functions for implementing security protocols on handheld devices. Our work refutes this. Specifically, we present a performance analysis focused on three of the most commonly used security protocols for networking applications, namely SSL, S/MIME and IPsec. Our results show that the time taken to perform cryptographic functions is small enough not to significantly impact real-time mobile transactions and that there is no obstacle to the use of quite sophisticated cryptographic protocols on handheld mobile devices.

Abstract: The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

Abstract: The Dynamic Source Routing protocol (DSR) is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. DSR allows the network to be completely self-organizing and self-configuring, without the need for any existing network infrastructure or administration. The protocol is composed of the two mechanisms of "Route Discovery" and "Route Maintenance", which work together to allow nodes to discover and maintain source routes to arbitrary destinations in the ad hoc network. The use of source routing allows packet routing to be trivially loop-free, avoids the need for up-to-date routing information in the intermediate nodes through which packets are forwarded, and allows nodes forwarding or overhearing packets to cache the routing information in them for their own future use. All aspects of the protocol operate entirely on-demand, allowing the routing packet overhead of DSR to scale automatically to only that needed to react to changes in the routes currently in use. This document specifies the operation of the DSR protocol for routing unicast IP packets in multi-hop wireless ad hoc networks.

Abstract: Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, ‘‘ad-hoc’’ network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANETs characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future. � 2003 Elsevier B.V. All rights reserved.

Abstract: This invention relates to methods for controlling and monitoring access to network servers. In particular, the process described in the invention includes client-server sessions over the Internet. In this environment, when the user attempts to access an access-controlled file, the server subjects the request to a secondary server which determines whether the client has an authorization or valid account. Upon such verification, the user is provided with a session identification which allows the user to access to the requested file as well as any other files within the present protection domain.

Abstract: Wireless networks are built upon a shared medium that makes it easy for adversaries to launch jamming-style attacks. These attacks can be easily accomplished by an adversary emitting radio frequency signals that do not follow an underlying MAC protocol. Jamming attacks can severely interfere with the normal operation of wireless networks and, consequently, mechanisms are needed that can cope with jamming attacks. In this paper, we examine radio interference attacks from both sides of the issue: first, we study the problem of conducting radio interference attacks on wireless networks, and second we examine the critical issue of diagnosing the presence of jamming attacks. Specifically, we propose four different jamming attack models that can be used by an adversary to disable the operation of a wireless network, and evaluate their effectiveness in terms of how each method affects the ability of a wireless node to send and receive packets. We then discuss different measurements that serve as the basis for detecting a jamming attack, and explore scenarios where each measurement by itself is not enough to reliably classify the presence of a jamming attack. In particular, we observe that signal strength and carrier sensing time are unable to conclusively detect the presence of a jammer. Further, we observe that although by using packet delivery ratio we may differentiate between congested and jammed scenarios, we are nonetheless unable to conclude whether poor link utility is due to jamming or the mobility of nodes. The fact that no single measurement is sufficient for reliably classifying the presence of a jammer is an important observation, and necessitates the development of enhanced detection schemes that can remove ambiguity when detecting a jammer. To address this need, we propose two enhanced detection protocols that employ consistency checking. The first scheme employs signal strength measurements as a reactive consistency check for poor packet delivery ratios, while the second scheme employs location information to serve as the consistency check. Throughout our discussions, we examine the feasibility and effectiveness of jamming attacks and detection schemes using the MICA2 Mote platform.