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Full-Text Articles in Physical Sciences and Mathematics

Cryptanalysis Of A Digital Signature Scheme On Id-Based Key-Sharing Infrastructures, Hongjun Wu, Feng Bao, Robert H. Deng Feb 2001

Cryptanalysis Of A Digital Signature Scheme On Id-Based Key-Sharing Infrastructures, Hongjun Wu, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

At ISW’99, Nishioka, Hanaoka and Imai proposed a digital signature scheme on ID-based key-sharing infrastructures. That signature scheme is claimed to be secure if the discrete logarithm problem is hard to solve. Two schemes (the ID-type and the random-type schemes) based on the linear scheme for the Key Predistribution Systems (KPS) and the discrete logarithm problem (DLP) were given. In this paper we show that those two schemes fail to meet the nonrepudiation requirement: with negligible amount of computation, a signature could be forged. For the ID-type signature scheme, any verifier could forge a signature to raise repudiation between that …


Cryptanalysis Of Two Sparse Polynomial Based Public Key Cryptosystems, Feng Bao, Robert H. Deng, Willi Geiselmann, Claus Schnorr, Rainer Steinwandt, Hongjun Wu Feb 2001

Cryptanalysis Of Two Sparse Polynomial Based Public Key Cryptosystems, Feng Bao, Robert H. Deng, Willi Geiselmann, Claus Schnorr, Rainer Steinwandt, Hongjun Wu

Research Collection School Of Computing and Information Systems

The application of sparse polynomials in cryptography has been studied recently. A public key encryption scheme EnRoot [4] and an identification scheme SPIFI [1] based on sparse polynomials were proposed. In this paper, we show that both of them are insecure. The designers of SPIFI proposed the modified SPIFI [2] after Schnorr pointed out some weakness in its initial version. Unfortunately, the modified SPIFI is still insecure. The same holds for the generalization of EnRoot proposed in [2].


A Framework For Performance And Value Assessment Of E-Business Systems In Corporate Travel Distribution, A.M. Chircu, Robert J. Kauffman Jan 2001

A Framework For Performance And Value Assessment Of E-Business Systems In Corporate Travel Distribution, A.M. Chircu, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

This chapter proposes and illustrates a framework that the authors call the value life cycle for e-commerce systems. Based on recent research results that relate to technology investments in the corporate travel industry and related theoretical and empirical perspectives, the authors lay out the corporate travel e-commerce system solutions value life cycle. The perspective involves estimating the maximum value that that an organization can obtain by implementing an e-commerce system in a specific industry and competitive environment. It also considers multiple factors that act as value contingencies for the implementation process. These create barriers to value accrual and to …


Ontologies And Electronic Commerce, Dieter Fensel, Deborah L. Mcguinness, Ellen Schulten, Wee-Keong Ng, Ee Peng Lim, Guanghao Yan Jan 2001

Ontologies And Electronic Commerce, Dieter Fensel, Deborah L. Mcguinness, Ellen Schulten, Wee-Keong Ng, Ee Peng Lim, Guanghao Yan

Research Collection School Of Computing and Information Systems

Ontologies are the first step toward realizing the full power of online e-commerce. Ontologies enable machine-understandable semantics of data, and building this data infrastructure will enable completely new kinds of automated services. Software agents can search for products, form buyer and seller coalitions, negotiate about products, or help automatically configure products and services according to specified user requirements. The combination of machine-processable semantics of data based on ontologies and the development of many specialized reasoning services will bring the Web to its full power. The authors discuss: taxonomies; information sources; future issues; business viewpoints; the e-marketplace; and B2B e-commerce standardisation …


Incorporating Window-Based Passage-Level Evidence In Document Retrieval, Wensi Xi, Richard Xu-Rong, Christopher Soo Guan Khoo, Ee Peng Lim Jan 2001

Incorporating Window-Based Passage-Level Evidence In Document Retrieval, Wensi Xi, Richard Xu-Rong, Christopher Soo Guan Khoo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

This study investigated whether document retrieval can be improved if documents are divided into smaller sub-documents or passages and the retrieval score for these passages are incorporated in the final retrieval score for the whole document. The documents were segmented by sliding a window of a certain size across the document and extracting the words displayed each time the window stopped. A retrieval score was calculated for each of the passages extracted and the highest score obtained by a passage of that size was taken as the document’s passage-level score for that window size. A range of window sizes was …