Eric Jui-Lin Lu

A SECURE NONREPUDIABLE THRESHOLD PROXY SIGNATURE SCHEME WITH KNOWN SIGNERS

In the (t;n) proxy signature scheme, the signature, originally signed by a signer, can be signed by t or more proxy signers out of a proxy group of n members. Recently, an efficient nonrepudiable threshold proxy signature scheme with known signers was proposed by H.-M. Sun. Suns scheme has two advantages. One is nonrepudiation. The proxy group cannot deny that having signed the proxy signature. Any verifier can identify the proxy group as a real signer. The other is identifiable signers. The verifier is able to identify the actual signers in the proxy group. Also, the signers cannot deny that having generated the proxy signature. In this article, we present a cryptanalysis of the Suns scheme. Further, we propose a secure, nonrepudiable and known signers threshold proxy signature scheme which remedies the weakness of the Suns scheme.

An empirical study of XML/EDI

Abstract Electronic data interchange (EDI) plays an important role in contemporary electronic commerce. It is believed that Extensible Markup Language (XML)/EDI will be the next generation of EDI. In this paper, we thoroughly study and analyze the XML/EDI framework proposed by the XML/EDI Group, and design as well as implement an XML/EDI prototype for Taiwans flower distribution channels. In accordance with the experiences obtained from the prototype development, we provide in depth analysis of the technology for XML developers and our observations of possible research opportunities in the applications of XML in electronic commerce. Also this paper proposes a general implementation procedure for the industries that are interested in the application of XML/EDI.

A new proxy signature scheme with revocation

In current proxy signature schemes, an original signer delegates her/his signing capability to a proxy signer, and then the proxy signer can sign messages on behalf of the original signer. Although these schemes have succeeded in proxy delegations, they are in general defective in proxy revocations. In this paper, we propose a proxy signature scheme which allows the original signer to revoke delegations whenever necessary.

Adding timestamps to the secure electronic auction protocol

Recently, Subramanian proposed a secure electronic auction protocol. It was claimed that the auction protocol ensured anonymity, security, privacy, atomicity, and low overhead. However, the sensitive information of payment, such as credit card number, can be revealed by the auctioneer. The bid can be forged by a malicious auctioneer. Also, the situation of two or more bidders who offered the same price was not resolved efficiently. In this paper, we will improve the robustness of this electronic auction protocol.

An empirical study of XML data management in business information systems

Due the popularity of XML, an increasingly large amount of business transactions encoded in XML have been exchanged on-line. Currently there are two approaches to process and manage these XML data. One is to store them in relational databases, and the other is to store them in recently-developed native XML databases. There is no conclusion yet as to which approach suits better for contemporary business information systems. Also, the effectiveness of native XML databases used in daily operational systems has not been completely investigated. Therefore, in this paper, we provide: (1) a complete and systematic survey of the current development and challenges of processing XML data in relational and native XML databases, (2) a useful benchmark for IT practitioners who need to process XML data effectively, (3) experimental results and detailed analysis which reveal several interesting tips that can be helpful to XML document designers, and (4) a conclusion, based on the findings of using native XML databases in EDI processes, that it is practical to use native XML databases for daily operations although our experimental results showed that relational database systems outperform native XML databases in processing XML data.

A massively parallel fast multipole algorithm in three dimensions

The simulation of many-body, many-particle systems has a wide range of applications in areas such as biophysics, chemistry, astrophysics, etc. It is known that the force calculation contributes 90% of the simulation time. This is mainly due to the fact that the total number of interactions in the force is O(N/sup 2/), where N is the number of particles in the system. The fast multipole algorithm proposed by Greengard and Rokhlin (1987) reduces the time complexity to O(N). In this paper, we design an efficient, parallel fast multipole algorithm in 3D. For portability, our parallel program is implemented using the Message Passing Interface. Is it possible to obtain high performance for a computationally-intensive application using a LAN of workstations? In this paper, we attempt to answer this question, which is commonly asked by those researchers who have no access to parallel computers or supercomputers.

ML-Chord: A multi-layered P2P resource sharing model

In recent years, due to the emergence of P2P technology, people rely on the Internet to share resources. It is believed that the number of users and shared resources will become enormously huge. As a result, many researches have been dedicated to improve the scalability and efficiency of P2P models. In this paper, we propose a multi-layered P2P resource sharing model, called ML-Chord, that assigns nodes into Chord-like layers based on the categories of shared resources. From the experimental results, it shows that ML-Chord is both efficient and scalable.

A relation metadata extension for SCORM Content Aggregation Model

To increase the interchangeability and reusability of learning objects, Advanced Distributed Learning Initiative suggested a set of metadata in SCORM Content Aggregation Model to describe learning objects and express relationships between learning objects. However, the suggested relations defined in the metadata of the SCORM CAM are limited. To resolve the problem, new relations were proposed by researchers. Unfortunately, some of the relations are redundant and even inappropriate. In addition, the usability of these relations has never been formally studied. Therefore, in this paper, we summarized and analyzed existing relations, removed duplicated relations, and developed a new relation metadata extension for SCORM CAM. Also, we surveyed 145 students in attempt to understand whether or not the proposed relations can increase their learning effectiveness. The results of the survey showed that learners agreed that the proposed relations are helpful.

Secret Hiding Mechanism Using QR Barcode

QR code is the commonly used two-dimensional (2D) barcode recently with the advantages of larger QR content and error correction capability. Based on the error correction property of QR code, we designed a secret hiding technique for QR barcode. The proposed scheme can conceal the secret data into the cover QR code without distorting the readability of QR content. That is, general browsers can read the QR content from the marked QR code for the sake of reducing attention. Only the authorized receiver can encrypt and retrieve the secret from the marked QR code. The secret payload of the designed scheme is adjustable. The scheme can convey larger secret into a QR code according to the selection of the QR version and the error correction level. The simulations demonstrate that the designed scheme is efficient and low computational complexity. The mechanism can be applied to the QR reader and mobile phone.

An XML multisignature scheme

Extensible markup language (XML) has become a standard format for data interchanges on the Internet especially in the electronic commerce. Although it is extremely important to protect XML documents from being illegally modified, the development of XML security is still in its infancy stage. One of major research areas in XML security is XML Signature. In the past, conventional multisignature schemes allow participant signers only sign on the whole document and thus make multisignature generations become inefficient. To overcome the problem, Wu et al. proposed a delegated multisignature scheme so that participant signers sign on the subdocuments that they are responsible. However, due to the rich structure of XML, all the multisignature schemes proposed so far are not appropriate for XML documents. In this paper, by utilizing the logical structure of XML and Wus scheme, we proposed an XML multisignature scheme. In our scheme, it inherits the merits of Wus scheme, further improves the efficiency in multisignature generation by signing the rules rather than the subdocuments, provides fine-grained control at the element level, and also is compatible with the XML Signature standard. Additionally, this scheme proposes a new signature generation approach that is based on the structure of the signed document rather than the signed document alone.