Year 2010 Issues on Cryptographic Algorithms

In the financial sector, cryptographic algorithms are used as fundamental techniques for assuring confidentiality and integrity of data used in financial transactions and for authenticating entities involved in the transactions. Currently, the most widely used algorithms appear to be two-key triple DES and RC4 for symmetric ciphers, RSA with a 1024-bit key for an asymmetric cipher and a digital signature, and SHA-1 for a hash function according to international standards and guidelines related to the financial transactions. However, according to academic papers and reports regarding the security evaluation for such algorithms, it is difficult to ensure enough security by using the algorithms for a long time period, such as 10 or 15 years, due to advances in cryptanalysis techniques, improvement of computing power, and so on. To enhance the transition to more secure ones, National Institute of Standards and Technology (NIST) of the United States describes in various guidelines that NIST will no longer approve two-key triple DES, RSA with a 1024-bit key, and SHA-1 as the algorithms suitable for IT systems of the U.S. Federal Government after 2010. It is an important issue how to advance the transition of the algorithms in the financial sector. This paper refers to issues regarding the transition as Year 2010 issues in cryptographic algorithms. To successfully complete the transition by 2010, the deadline set by NIST, it is necessary for financial institutions to begin discussing the issues at the earliest possible date. This paper summarizes security evaluation results of the current algorithms, and describes Year 2010 issues, their impact on the financial industry, and the transition plan announced by NIST. This paper also shows several points to be discussed when dealing with Year 2010 issues.Cryptographic algorithm; Symmetric cipher; Asymmetric cipher; Security; Year 2010 issues; Hash function

Study of Fully Homomorphic Encryption over Integers

Fully homomorphic encryption has long been regarded as an open problem of cryptography. The method of constructing first fully homomorphic encryption scheme by Gentry is complicate so that it has been considered difficult to understand. This paper explains the idea of constructing fully homomorphic encryption and presents a general framework from various scheme of fully homomorphic encryption. Specially, this general framework can show some possible ways to construct fully homomorphic encryption. We then analyze the procedure how to obtaining fully homomorphic encryption over the integers. The analysis of recrypt procedure show the growth of noise, and the bound of noise in recrypt procedure is given. Finally, we describe the steps of implementation.

Watermarking protocol for protecting user\u27s right in content based image retrieval

Content based image retrieval (CBIR) is a technique to search for images relevant to the user&rsquo;s query from an image collection.In last decade, most attention has been paid to improve the retrieval performance. However, there is no significant effort to investigate the security concerning in CBIR. Under the query by example (QBE) paradigm, the user supplies an image as a query and the system returns a set of retrieved results. If the query image includes user&rsquo;s private information, an untrusted server provider of CBIR may distribute it illegally, which leads to the user&rsquo;s right problem. In this paper, we propose an interactive watermarking protocol to address this problem. A watermark is inserted into the query image by the user in encrypted domain without knowing the exact content. The server provider of CBIR will get the watermarked query image and uses it to perform image retrieval. In case where the user finds an unauthorized copy, a watermark in the unauthorized copy will be used as evidence to prove that the user&rsquo;s legal right is infringed by the server provider.<br /

Data Mining in Electronic Commerce

Modern business is rushing toward e-commerce. If the transition is done properly, it enables better management, new services, lower transaction costs and better customer relations. Success depends on skilled information technologists, among whom are statisticians. This paper focuses on some of the contributions that statisticians are making to help change the business world, especially through the development and application of data mining methods. This is a very large area, and the topics we cover are chosen to avoid overlap with other papers in this special issue, as well as to respect the limitations of our expertise. Inevitably, electronic commerce has raised and is raising fresh research problems in a very wide range of statistical areas, and we try to emphasize those challenges.Comment: Published at http://dx.doi.org/10.1214/088342306000000204 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

On Protocols for Information Security Services

Now-a-days, organizations are becoming more and more dependent on their information systems due to the availability of high technology environment.Information is also treated as vital like other important assets of an organization. Thus, we require Information Security Services (ISS) protocols to protect this commodity. In this thesis, investigations have been made to protect information by developing some ISS protocols. We proposed a key management protocol, which stores one-way hash of the password at the server, instead of storing plaintext version of password.Every host and server agrees upon family of commutative one-way hash functions. Due to this prevention mechanism, online and offline guessing attacks are defeated. The protocol provides host authentication. As a result, man-in-the-middle attack is averted. It also withstands malicious insider attack

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

Security, privacy and trust in wireless mesh networks

With the advent of public key cryptography, digital signature schemes have been extensively studied in order to minimize the signature sizes and to accelerate their execution while providing necessary security properties. Due to the privacy concerns pertaining to the usage of digital signatures in authentication schemes, privacy-preserving signature schemes, which provide anonymity of the signer, have attracted substantial interest in research community. Group signature algorithms, where a group member is able to sign on behalf of the group anonymously, play an important role in many privacy-preserving authentication/ identification schemes. On the other hand, a safeguard is needed to hold users accountable for malicious behavior. To this end, a designated opening/revocation manager is introduced to open a given anonymous signature to reveal the identity of the user. If the identified user is indeed responsible for malicious activities, then s/he can also be revoked by the same entity. A related scheme named direct anonymous attestation is proposed for attesting the legitimacy of a trusted computing platform while maintaining its privacy. This dissertation studies the group signature and direct anonymous attestation schemes and their application to wireless mesh networks comprising resource-constrained embedded devices that are required to communicate securely and be authenticated anonymously, while malicious behavior needs to be traced to its origin. Privacy-aware devices that anonymously connect to wireless mesh networks also need to secure their communication via efficient symmetric key cryptography, as well. In this dissertation, we propose an efficient, anonymous and accountable mutual authentication and key agreement protocol applicable to wireless mesh networks. The proposed scheme can easily be adapted to other wireless networks. The proposed scheme is implemented and simulated using cryptographic libraries and simulators that are widely deployed in academic circles. The implementation and simulation results demonstrate that the proposed scheme is effective, efficient and feasible in the context of hybrid wireless mesh networks, where users can also act as relaying agents. The primary contribution of this thesis is a novel privacy-preserving anonymous authentication scheme consisting of a set of protocols designed to reconcile user privacy and accountability in an efficient and scalable manner in the same framework. The three-party join protocol, where a user can connect anonymously to the wireless mesh network with the help of two semi-trusted parties (comprising the network operator and a third party), is efficient and easily applicable in wireless networks settings. Furthermore, two other protocols, namely two-party identification and revocation protocols enable the network operator, with the help of the semi-trusted third party, to trace suspected malicious behavior back to its origins and revoke users when necessary. The last two protocols can only be executed when the two semi-trusted parties cooperate to provide accountability. Therefore, the scheme is protected against an omni-present authority (e.g. network operator) violating the privacy of network users at will. We also provide arguments and discussions for security and privacy of the proposed scheme