Security and reliability of LPDC based public-key cryptosystems

Security and reliability of LDPC based public-key cryptosystems are discussed and analysed. We study attacks on the cryptosystem when partial knowledge of one or more of the private key components and/or of the plaintext have been acquired.

Analysis of common attacks in public-key cryptosystems based on low-density parity-check codes

The security and reliability of a class of public-key cryptosystems against attacks by unauthorized parties, who had acquired partial knowledge of one or more of the private key components and/or of the message, were discussed. The standard statistical mechanical methods of dealing with diluted spin systems with replica symmetric considerations were analyzed. The dynamical transition which defined decryption success in practical situation was studied. The phase diagrams which showed the dynamical threshold as a function of the partial acquired knowledge of the private key were also presented.

Cryptographic techniques for personal communication systems security

The advent of personal communication systems within the last decade has depended upon the utilization of advanced digital schemes for source and channel coding and for modulation. The inherent digital nature of the communications processing has allowed the convenient incorporation of cryptographic techniques to implement security in these communications systems. There are various security requirements, of both the service provider and the mobile subscriber, which may be provided for in a personal communications system. Such security provisions include the privacy of user data, the authentication of communicating parties, the provision for data integrity, and the provision for both location confidentiality and party anonymity. This thesis is concerned with an investigation of the private-key and public-key cryptographic techniques pertinent to the security requirements of personal communication systems and an analysis of the security provisions of Second-Generation personal communication systems is presented. Particular attention has been paid to the properties of the cryptographic protocols which have been employed in current Second-Generation systems. It has been found that certain security-related protocols implemented in the Second-Generation systems have specific weaknesses. A theoretical evaluation of these protocols has been performed using formal analysis techniques and certain assumptions made during the development of the systems are shown to contribute to the security weaknesses. Various attack scenarios which exploit these protocol weaknesses are presented. The Fiat-Sharmir zero-knowledge cryptosystem is presented as an example of how asymmetric algorithm cryptography may be employed as part of an improved security solution. Various modifications to this cryptosystem have been evaluated and their critical parameters are shown to be capable of being optimized to suit a particular applications. The implementation of such a system using current smart card technology has been evaluated.

Human resource management in the Indian public and private sectors:an empirical comparison

This study compares human resource management (HRM) practices in Indian public- and private-sector organizations. The investigation is based on a questionnaire survey of 137 large manufacturing firms (public sector = 81: private sector = 56). The key areas of analysis include the structure of human resource (HR) department, the role of HR function in corporate change, recruitment and selection, pay and benefits, training and development, employee relations and emphasis on key HRM strategies. Internal labour markets (ILMs) are used to make the comparative analysis. The statistical results show a number of similarities and differences in the HRM systems of Indian public-and private-sector organizations. Against the established notion, the results of this study reveal that the gap between Indian private- and public-sector HRM practices is not very significant. Moreover, in a few HR functional areas (for example, compensation and training and development), Indian private-sector firms have adopted a more rational approach than their public-sector counterparts. © 2004 Taylor and Francis Ltd.

Does competitive entry structurally change key marketing metrics?

To what extent does competitive entry create a structural change in key marketing metrics? New players may just be a temporal nuisance to incumbents, but could also fundamentally change the latter's performance evolution, or induce them to permanently alter their spending levels and/or pricing decisions. Similarly, the addition of a new marketing channel could permanently shift shopping preferences, or could just create a short-lived migration from existing channels. The steady-state impact of a given entry or channel addition on various marketing metrics is intrinsically an empirical issue for which we need an appropriate testing procedure. In this study, we introduce a testing sequence that allows for the endogenous determination of potential change (break) locations, thereby accounting for lead and/or lagged effects of the introduction of interest. By not restricting the number of potential breaks to one (as is commonly done in the marketing literature), we quantify the impact of the new entrant(s) while controlling for other events that may have taken place in the market. We illustrate the methodology in the context of the Dutch television advertising market, which was characterized by the entry of several late movers. We find that the steady-state growth of private incumbents' revenues was slowed by the quasi-simultaneous entry of three new players. Contrary to industry observers' expectations, such a slowdown was not experienced in the related markets of print and radio advertising.

Networked governance and the regulation of expression on the Internet:the blurring of the role of public and private actors as content regulators

This editorial provides an overview of the themes of network governance and content regulation that are expanded upon in the subsequent articles, identifying key issues and concerns that are prevalent in the literature in this field. In particular, this text considers governance not as an Internet-specific phenomenon, but as a global phenomenon, identifying and discussing literature pertaining to governance both online and offline, and providing examples of theories that seek to explain these forms of governance. Focusing on the interaction between public and private actors in content regulation, this editorial highlights that content regulation is a complex and contested issue that cannot be separated from its social and cultural contexts, and provides an overview of the articles contained.

Dialogue, partnership and empowerment for network and information security:the changing role of the private sector from objects of regulation to regulation shapers

The protection of cyberspace has become one of the highest security priorities of governments worldwide. The EU is not an exception in this context, given its rapidly developing cyber security policy. Since the 1990s, we could observe the creation of three broad areas of policy interest: cyber-crime, critical information infrastructures and cyber-defence. One of the main trends transversal to these areas is the importance that the private sector has come to assume within them. In particular in the area of critical information infrastructure protection, the private sector is seen as a key stakeholder, given that it currently operates most infrastructures in this area. As a result of this operative capacity, the private sector has come to be understood as the expert in network and information systems security, whose knowledge is crucial for the regulation of the field. Adopting a Regulatory Capitalism framework, complemented by insights from Network Governance, we can identify the shifting role of the private sector in this field from one of a victim in need of protection in the first phase, to a commercial actor bearing responsibility for ensuring network resilience in the second, to an active policy shaper in the third, participating in the regulation of NIS by providing technical expertise. By drawing insights from the above-mentioned frameworks, we can better understand how private actors are involved in shaping regulatory responses, as well as why they have been incorporated into these regulatory networks.