Synchronization of multi-carrier CDMA signals and security on internet.

by Yooh Ji Heng.Thesis (M.Phil.)--Chinese University of Hong Kong, 1996.Includes bibliographical references (leaves 119-128).Appendix in Chinese.Chapter I --- Synchronization of Multi-carrier CDMA Signals --- p.1Chapter 1 --- Introduction --- p.2Chapter 1.1 --- Spread Spectrum CDMA --- p.4Chapter 1.1.1 --- Direct Sequence/SS-CDMA --- p.5Chapter 1.1.2 --- Frequency Hopping/SS-CDMA --- p.5Chapter 1.1.3 --- Pseudo-noise Sequence --- p.6Chapter 1.2 --- Synchronization for CDMA signal --- p.7Chapter 1.2.1 --- Acquisition of PN Sequence --- p.7Chapter 1.2.2 --- Phase Locked Loop --- p.8Chapter 2 --- Multi-carrier CDMA --- p.10Chapter 2.1 --- System Model --- p.11Chapter 2.2 --- Crest Factor --- p.12Chapter 2.3 --- Shapiro-Rudin Sequence --- p.14Chapter 3 --- Synchronization and Detection by Line-Fitting --- p.16Chapter 3.1 --- Unmodulated Signals --- p.16Chapter 3.2 --- Estimating the Time Shift by Line-Fitting --- p.19Chapter 3.3 --- Modulated Signals --- p.22Chapter 4 --- Matched Filter --- p.23Chapter 5 --- Performance and Conclusion --- p.27Chapter 5.1 --- Line Fitting Algorithm --- p.27Chapter 5.2 --- Matched Filter --- p.28Chapter 5.3 --- Conclusion --- p.30Chapter II --- Security on Internet --- p.31Chapter 6 --- Introduction --- p.32Chapter 6.1 --- Introduction to Cryptography --- p.32Chapter 6.1.1 --- Classical Cryptography --- p.33Chapter 6.1.2 --- Cryptanalysis --- p.35Chapter 6.2 --- Introduction to Internet Security --- p.35Chapter 6.2.1 --- The Origin of Internet --- p.35Chapter 6.2.2 --- Internet Security --- p.36Chapter 6.2.3 --- Internet Commerce --- p.37Chapter 7 --- Elementary Number Theory --- p.39Chapter 7.1 --- Finite Field Theory --- p.39Chapter 7.1.1 --- Euclidean Algorithm --- p.40Chapter 7.1.2 --- Chinese Remainder Theorem --- p.40Chapter 7.1.3 --- Modular Exponentiation --- p.41Chapter 7.2 --- One-way Hashing Function --- p.42Chapter 7.2.1 --- MD2 --- p.43Chapter 7.2.2 --- MD5 --- p.43Chapter 7.3 --- Prime Number --- p.44Chapter 7.3.1 --- Listing of Prime Number --- p.45Chapter 7.3.2 --- Primality Testing --- p.45Chapter 7.4 --- Random/Pseudo-Random Number --- p.47Chapter 7.4.1 --- Examples of Random Number Generator --- p.49Chapter 8 --- Private Key and Public Key Cryptography --- p.51Chapter 8.1 --- Block Ciphers --- p.51Chapter 8.1.1 --- Data Encryption Standard (DES) --- p.52Chapter 8.1.2 --- International Data Encryption Algorithm (IDEA) --- p.54Chapter 8.1.3 --- RC5 --- p.55Chapter 8.2 --- Stream Ciphers --- p.56Chapter 8.2.1 --- RC2 and RC4 --- p.57Chapter 8.3 --- Public Key Cryptosystem --- p.58Chapter 8.3.1 --- Diffie-Hellman --- p.60Chapter 8.3.2 --- Knapsack Algorithm --- p.60Chapter 8.3.3 --- RSA --- p.62Chapter 8.3.4 --- Elliptic Curve Cryptosystem --- p.63Chapter 8.3.5 --- Public Key vs. Private Key Cryptosystem --- p.64Chapter 8.4 --- Digital Signature --- p.65Chapter 8.4.1 --- ElGamal Signature Scheme --- p.66Chapter 8.4.2 --- Digital Signature Standard (DSS) --- p.67Chapter 8.5 --- Cryptanalysis to Current Cryptosystems --- p.68Chapter 8.5.1 --- Differential Cryptanalysis --- p.68Chapter 8.5.2 --- An Attack to RC4 in Netscapel.l --- p.69Chapter 8.5.3 --- "An Timing Attack to Diffie-Hellman, RSA" --- p.71Chapter 9 --- Network Security and Electronic Commerce --- p.73Chapter 9.1 --- Network Security --- p.73Chapter 9.1.1 --- Password --- p.73Chapter 9.1.2 --- Network Firewalls --- p.76Chapter 9.2 --- Implementation for Network Security --- p.79Chapter 9.2.1 --- Kerberos --- p.79Chapter 9.2.2 --- Privacy-Enhanced Mail (PEM) --- p.80Chapter 9.2.3 --- Pretty Good Privacy (PGP) --- p.82Chapter 9.3 --- Internet Commerce --- p.83Chapter 9.3.1 --- Electronic Cash --- p.85Chapter 9.4 --- Internet Browsers --- p.87Chapter 9.4.1 --- Secure NCSA Mosaic --- p.87Chapter 9.4.2 --- Netscape Navigator --- p.89Chapter 9.4.3 --- SunSoft HotJava --- p.91Chapter 10 --- Examples of Electronic Commerce System --- p.94Chapter 10.1 --- CyberCash --- p.95Chapter 10.2 --- DigiCash --- p.97Chapter 10.3 --- The Financial Services Technology Consortium --- p.98Chapter 10.3.1 --- Electronic Check Project --- p.99Chapter 10.3.2 --- Electronic Commerce Project --- p.101Chapter 10.4 --- FirstVirtual --- p.103Chapter 10.5 --- Mondex --- p.104Chapter 10.6 --- NetBill --- p.106Chapter 10.7 --- NetCash --- p.108Chapter 10.8 --- NetCheque --- p.111Chapter 11 --- Conclusion --- p.113Chapter A --- An Essay on Chinese Remainder Theorem and RSA --- p.115Bibliography --- p.11

Identity based blind signaturescheme based upon DLP

Blind Signature scheme deals with the concept where requester sends the request that the signer should sign on a blind message. Anyone can verify the signature after publishing the information without any restriction. The proposed scheme having the property of both concept, Identity based as well as Blind Signature using DLP. With the help of Identity Based system we can easily archive the public key certification without key-management setting. In several ID based scheme ID map into an Elliptic curve, but we have a novel techniques to solve this problem. We have proposed a scheme that is based on Discrete logarithm problem.We have proved that our scheme meets all essential and secondary security prematurity. In addition we have given the mathematically and pragmatically correctness of our scheme. As our best of knowledge, we give the first discussion on these two notation. Also, we proved that our scheme fulfill all criteria that should be meet in a blind signature scheme.Our proposed scheme can be used in an E-commerce, E-voting and E-cashing anywhere without any restriction.We have given an application of E-cashing using our scheme

Cryptography and Its Applications in Information Security

Nowadays, mankind is living in a cyber world. Modern technologies involve fast communication links between potentially billions of devices through complex networks (satellite, mobile phone, Internet, Internet of Things (IoT), etc.). The main concern posed by these entangled complex networks is their protection against passive and active attacks that could compromise public security (sabotage, espionage, cyber-terrorism) and privacy. This Special Issue “Cryptography and Its Applications in Information Security” addresses the range of problems related to the security of information in networks and multimedia communications and to bring together researchers, practitioners, and industrials interested by such questions. It consists of eight peer-reviewed papers, however easily understandable, that cover a range of subjects and applications related security of information

Critical Perspectives on Provable Security: Fifteen Years of Another Look Papers

We give an overview of our critiques of “proofs” of security and a guide to our papers on the subject that have appeared over the past decade and a half. We also provide numerous additional examples and a few updates and errata

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

Proceedings of the 2nd International Workshop on Security in Mobile Multiagent Systems

This report contains the Proceedings of the Second Workshop on Security on Security of Mobile Multiagent Systems (SEMAS2002). The Workshop was held in Montreal, Canada as a satellite event to the 5th International Conference on Autonomous Agents in 2001. The far reaching influence of the Internet has resulted in an increased interest in agent technologies, which are poised to play a key role in the implementation of successful Internet and WWW-based applications in the future. While there is still considerable hype concerning agent technologies, there is also an increasing awareness of the problems involved. In particular, that these applications will not be successful unless security issues can be adequately handled. Although there is a large body of work on cryptographic techniques that provide basic building-blocks to solve specific security problems, relatively little work has been done in investigating security in the multiagent system context. Related problems are secure communication between agents, implementation of trust models/authentication procedures or even reflections of agents on security mechanisms. The introduction of mobile software agents significantly increases the risks involved in Internet and WWW-based applications. For example, if we allow agents to enter our hosts or private networks, we must offer the agents a platform so that they can execute correctly but at the same time ensure that they will not have deleterious effects on our hosts or any other agents / processes in our network. If we send out mobile agents, we should also be able to provide guarantees about specific aspects of their behaviour, i.e., we are not only interested in whether the agents carry out-out their intended task correctly. They must defend themselves against attacks initiated by other agents, and survive in potentially malicious environments. Agent technologies can also be used to support network security. For example in the context of intrusion detection, intelligent guardian agents may be used to analyse the behaviour of agents on a firewall or intelligent monitoring agents can be used to analyse the behaviour of agents migrating through a network. Part of the inspiration for such multi-agent systems comes from primitive animal behaviour, such as that of guardian ants protecting their hill or from biological immune systems

Tag Ownership Transfer in Radio Frequency Identification Systems: A Survey of Existing Protocols and Open Challenges

Radio frequency identification (RFID) is a modern approach to identify and track several assets at once in a supply chain environment. In many RFID applications, tagged items are frequently transferred from one owner to another. Thus, there is a need for secure ownership transfer (OT) protocols that can perform the transfer while, at the same time, protect the privacy of owners. Several protocols have been proposed in an attempt to fulfill this requirement. In this paper, we provide a comprehensive and systematic review of the RFID OT protocols that appeared over the years of 2005-2018. In addition, we compare these protocols based on the security goals which involve their support of OT properties and their resistance to attacks. From the presented comparison, we draw attention to the open issues in this field and provide suggestions for the direction that future research should follow. Furthermore, we suggest a set of guidelines to be considered in the design of new protocols. To the best of our knowledge, this is the first comprehensive survey that reviews the available OT protocols from the early start up to the current state of the art

Privacy-preserving efficient searchable encryption

Data storage and computation outsourcing to third-party managed data centers, in environments such as Cloud Computing, is increasingly being adopted by individuals, organizations, and governments. However, as cloud-based outsourcing models expand to society-critical data and services, the lack of effective and independent control over security and privacy conditions in such settings presents significant challenges. An interesting solution to these issues is to perform computations on encrypted data, directly in the outsourcing servers. Such an approach benefits from not requiring major data transfers and decryptions, increasing performance and scalability of operations. Searching operations, an important application case when cloud-backed repositories increase in number and size, are good examples where security, efficiency, and precision are relevant requisites. Yet existing proposals for searching encrypted data are still limited from multiple perspectives, including usability, query expressiveness, and client-side performance and scalability. This thesis focuses on the design and evaluation of mechanisms for searching encrypted data with improved efficiency, scalability, and usability. There are two particular concerns addressed in the thesis: on one hand, the thesis aims at supporting multiple media formats, especially text, images, and multimodal data (i.e. data with multiple media formats simultaneously); on the other hand the thesis addresses client-side overhead, and how it can be minimized in order to support client applications executing in both high-performance desktop devices and resource-constrained mobile devices. From the research performed to address these issues, three core contributions were developed and are presented in the thesis: (i) CloudCryptoSearch, a middleware system for storing and searching text documents with privacy guarantees, while supporting multiple modes of deployment (user device, local proxy, or computational cloud) and exploring different tradeoffs between security, usability, and performance; (ii) a novel framework for efficiently searching encrypted images based on IES-CBIR, an Image Encryption Scheme with Content-Based Image Retrieval properties that we also propose and evaluate; (iii) MIE, a Multimodal Indexable Encryption distributed middleware that allows storing, sharing, and searching encrypted multimodal data while minimizing client-side overhead and supporting both desktop and mobile devices