Further analysis of the Internet key exchange protocol
Secure communication over the Internet becomes an essential requirement for any value-added Internet application. The use of cryptography for secure communication brings out the requirement of cryptographic key management. This paper examines some security issues on the Internet Key Exchange (IKE) protocol specified in RFC 2409. The investigation is intended for clarifying some specification ambiguities in RFC 2409 and facilitating a correct implementation of the IKE protocol.

title: An intensive survey of fair non-repudiation protocols
abstract: With the phenomenal growth of the Internet and open networks in general, security services, such as non-repudiation, become crucial to many applications. Non-repudiation services must ensure that when Alice sends some information to Bob over a network, neither Alice nor Bob can deny having participated in a part or the whole of this communication. Therefore a fair non-repudiation protocol has to generate non-repudiation of origin evidences intended to Bob, and non-repudiation of receipt evidences destined to Alice. In this paper, we clearly define the properties a fair non-repudiation protocol must respect, and give a survey of the most important non-repudiation protocols without and with trusted third party (TTP). For the later ones we discuss the evolution of the TTP's involvement and, between others, describe the most recent protocol using a transparent TTP. We also discuss some ad-hoc problems related to the management of non-repudiation evidences.

title: Non-Repudiation in Electronic Commerce
abstract: Electronic Commerce and Security. Repudiation and Dispute Resolution. Non-Repudiation and Network Security. Non-Repudiation in Message Handling Systems. Non-Repudiation in Electronic Payment Systems. Book Outline. Fundamentals of Non-Repudiation - Goals of Non-Repudiation. Non-Repudiation Services. Non-Repudiation Evidence. Roles of Trusted Third Parties. Phases of Non-Repudiation. Non-Repudiation Policy. Requirements for Non-Repudiation. Securing Digital Signatures for Non-Repudiation - Security Requirements on Digital Signatures. Time Stamps in Digital Signatures. Securing TTP's Digital Signatures. Time-Stamping Approach.  One-Way Sequential Link Approach.   Achieving Fair Non-Repudiation - Factors against Fair Non-Repudiation. Approaches for Fair Non-Repudiation.  Using Light-Weighted On-Line TTP.  Using Off-Line TTP without Timely Termination.  Using Off-Line TTP with Timely Termination.  Using In-Line TTP for Timely Delivery.  Related Work on Fair Non-Repudiation - Protocols Using In-Line TTP. Protocols Using On-Line TTP. Protocols Using Off-Line TTP. Protocols with Probablistic Fairness.  ISO's Non-Repudiation Mechanisms - Overview of ISO/IEC 13888. Mechanisms Using Symmetric Techniques. Mechanisms Using Asymmetric Techniques. Time-Stamping Evidence.  Case Studies - Non-Repudiation in Electronic Payment. Undeniable Billing in Mobile Communication.  Towards Formal Verification of Non-Repudiation - The SVO Logic. Formalization of Non-Repudiation. Verification of a Non-Repudiation Protocol.

title: Agent-mediated non-repudiation protocols
abstract: Non-repudiation is a security service that provides cryptographic evidence to support the settlement of disputes in electronic commerce. In commercial transactions, an intermediary (or agent) might be involved to help transacting parties to conduct their business. Nevertheless, such an intermediary may not be fully trusted. In this paper, we propose agent-mediated non-repudiation protocols and analyze their security requirements. We first present a simple scenario with only one recipient, followed by a more complicated framework where multiple recipients are involved and collusion between them is possible. We also identify applications that could take advantage of these agent-mediated nonrepudiation protocols.

title: Efficient Signature Validation Based on a New PKI
abstract: Digital signatures usually serve as irrefutable cryptographic evidence to support dispute resolution in electronic transactions. Trusted time-stamping and certificate revocation services, although very costly in practice, must be available to prevent big loss due to compromising of the signing key. In this paper, we employ a revocation-free public-key framework to improve the efficiency in maintaining the validity of digital signatures as non-repudiation evidence. The new PKI allows an end user to control the validity of his own public-key certificate and enables certificate verification without retrieving the revocation information from the CA. Based on this new PKI, we could validate generic digital signatures using a TSA only. Moreover, we could validate forward-secure digital signatures without the TTP’s involvement.

title: Securing digital signatures for non-repudiation
abstract: Dispute of transactions is a common problem that could jeopardise business. Hence non-repudiation services are essential in business transactions which provide evidence to enable dispute resolution. To be eligible as non-repudiation evidence, the digital signature on an electronic document should remain valid until its expiry date which is specified by some non-repudiation policy. The conventional approaches are either inefficient or insecure to achieve non-repudiation in electronic commerce. This article presents a practical scheme to secure digital signatures as non-repudiation evidence with an adjustable degree of risk.

title: Data driven approach to designing minimum hamming distance polychotomizer
abstract: A polychotomous classifier assigns an observation to one of the K categories with K > = 3. Multiple binary classifiers (K = 2) such as the popular Support Vector Machines can be combined to achieve multi-class classification. Commonly used approaches include the one-vs-others scheme and the one-vs-one (pairwise coupling) scheme. While literature reported better performance from pairwise coupling than one-vs-others, the number of base learners required by pairwise coupling is quadratic in K. Alternatively, error correcting output codes (ECOC) provides a more general framework for designing polychotomizers. It associates each class with a codeword, which provides the capability to unify the traditional schemes. However, the design of an effective "coding matrix" remains an open problem. We study one kind of ECOC polychotomizer that decodes using minimum hamming distance. We propose a novel data-driven way to design the codewords based on inter-cluster distance. It provides a systematic way to extend the traditional schemes and construct effective polychotomizers. Experiments are conducted on synthetic data and real world applications including UCI repository problems and CENPARMI handwritten numerals. Experiments show that the proposed scheme can achieve competitive accuracy compared with both traditional schemes, and the number of base learners is typically much less than the requirement of the pairwise scheme.

title: Code Parameterization for Satisfaction of QoS Requirements in Embedded Software
abstract: The rapid growth of embedded systems urgently requires methods of improving the development process for these systems. Component-based development (CBD) techniques have been widely studied to enhance the productivity of developing complex applications. These techniques can benefit the software development process for embedded systems as well as other application domains. However, applying CBD techniques to embedded software development faces additional challenges. For embedded systems, it is crucial to consider the QoS attributes, such as timeliness, memory limitations, output precision, battery constraints, etc. However, it is often difficult to adjust the QoS properties of a system integrated from components that do not consider QoS properties in the first place. In this paper, we present an overview of a repository-based embedded software development methodology and then focus on component parameterization techniques. The basic concept of the parameterization process is to identify configurable parameters in a component that can be parameterized to achieve QoS tradeoffs. The component is then modified to a reconfigurable one such that its configurable parameters can be adjusted to satisfy different QoS requirements for various applications or for dynamical changing execution environment. A rule base is used to assist the parameter identification process. We also develop delta file technique to facilitate component adaptation and testing tools for QoS data collection. Keywords-embedded system, component parameterization, QoS, Repository system

title: Regularized B-spline network and its application to heart arrhythmia classification
abstract: This paper presents an effective learning scheme that combines B-spline modeling and regularized neural networks. Essential issues of structural design and learning process are discussed. Regularization theory is leveraged to design the topological structure of the network. A training algorithm is derived for the learning of both synaptic weights and B-spline coefficients. The approach is then applied to the medical problem of heart arrhythmia detection, particularly the detection of premature ventricular contraction. Promising results demonstrate the potential benefits of the proposed method.

title: Performance Evaluation of Directional Adaptive Range Control in Mobile Ad Hoc Networks
abstract: This paper presents DARC (Directional Adaptive Range Control), a range control mechanism using directional antennas to be implemented across multiple layers. DARC uses directional reception for range control rather than directional transmission in order to achieve both range extension and high spatial reuse. It adaptively controls the communication range by estimating dynamically changing local network density based on the transmission activities around each network node. The experimental results using simulation with detailed physical layer, IEEE 802.11 DCF MAC, and AODV protocol models have shown the successful adaptation of communication range with DARC for varied network densities and traffic loads. DARC improves the packet delivery ratio by a factor of 9 at the maximum for sparse networks while it maintains the increased network capacity for dense networks. Further, as each node adaptively changes the communication range, the network delivers up to 20% more packets with DARC compared to any fixed range configurations.

title: An Overlay Subscription Network for Live Internet TV Broadcast
abstract: We propose a framework, called overlay subscription network (OSN), for live Internet TV broadcast, where a subscriber can choose to watch at any time. This framework allows the source server to incrementally build a topology graph that contains the network connections not only from the server to each subscriber, but also among the subscribers themselves. With such a topology graph in place, we consider efficient overlay multicast for scalable OSN services. We first show that idling nodes, which do not receive video data for their own playback, can actually be used for data forwarding to significantly reduce the cost of overlay multicast. In light of this observation, we then propose a novel overlay multicast technique that distinguishes itself from existing schemes with these three aspects. First, the proposed technique is centered on the topology graph and can take advantage of the actual network connections among the subscribing nodes. Second, the new scheme is able to find and incorporate appropriate idling nodes in multicast to reduce network traffic. Third, with our approach, a node can be used in multiple multicast trees for data forwarding to improve the overall system performance. We evaluate the performance of the proposed technique through simulation. Our extensive studies show that the proposed framework has the potential to enable the Internet, a vehicle up to date mainly for transferring text and image data, for large-scale and cost-effective TV broadcast