JWSR,Volume 5, number 3, July- September 2008
Official Publication of the Information Resources Management Association
Published: Quarterly in Print and Electronically
ISSN: 1545-7362
EISSN: 1546-5004


RESEARCH PAPERS

PAPER ONE:

“XML Security with Binary XML for Mobile Web Services”

Kangasharju, Jaakko; Lindholm, Tancred; Tarkoma, Sasu

In the wireless world, there has recently been much interest in alternate serialization formats for XML data, mostly driven by the weak capabilities of both devices and networks. However, it is difficult to make an alternate serialization format compatible with XML security features such as encryption and signing. We consider here ways to integrate an alternate format with security, and present a solution that we see as a viable alternative. In addition to this, we present extensive performance measurements, including ones on a mobile phone on the effect of an alternate format when using XML-based security. These measurements indicate that, in the wireless world, reducing message sizes is the most pressing concern, and that processing efficiency gains of an alternate format are a much smaller concern. We also make specific recommendations on security usage based on our measurements.

To obtain a copy of the entire article, click on the link below.
http://www.igi-global.com/articles/details.asp?ID=8237

PAPER TWO:

“An Access-Control Framework for WS-BPEL”

Paci, Frederica; Bertino, Elisa; Crampton, Jason

Business processes, the next-generation workflows, have attracted considerable research interest in the last 15 years. More recently, several XML-based languages have been proposed for specifying and orchestrating business processes, resulting in the WS-BPEL language. Even if WS-BPEL has been developed to specify automated business processes that orchestrate activities of multiple Web services, there are many applications and situations requiring that people be considered as additional participants who can influence the execution of a process. Significant omissions from WS-BPEL are the specification of activities that require interactions with humans to be completed, called human activities, and the specification of authorization information associating users with human activities in a WS-BPEL business process and authorization constraints, such as separation of duty, on the execution of human activities. In this article, we address these deficiencies by introducing a new type of WS-BPEL activity to model human activities and by developing RBAC-WS-BPEL, a role-based access-control model for WS-BPEL, and BPCL, a language to specify authorization constraints.

To obtain a copy of the entire article, click on the link below.
http://www.igi-global.com/articles/details.asp?ID=8238

PAPER THREE:

“XML Compression for Web Services on Resource-Constrained Devices”

Werner, Christian; Buschmann, Carsten; Brandt, Ylva; Fischer, Stefan

Compared to other middleware approaches like CORBA or Java RMI the protocol overhead of SOAP is very high. This fact is not only disadvantageous for several performance-critical applications, but especially in environments with limited network bandwidth or resource-constrained computing devices. Although recent research work concentrated on more compact, binary representations of XML data only very few approaches account for the special characteristics of SOAP communication. In this article we will discuss the most relevant state-of-the-art technologies for compressing XML data. Furthermore, we will present a novel solution for compacting SOAP messages. In order to achieve significantly better compression rates than current approaches, our compressor utilizes structure information from an XML Schema or WSDL document. With this additional knowledge on the grammar of the exchanged messages, our compressor generates a single custom pushdown automaton, which can be used as a highly efficient validating parser as well as a highly efficient compressor. The main idea is to tag the transitions of the automaton with short binary identifiers that are then used to encode the path trough the automaton during parsing. Our approach leads to extremely compact data representations and is also usable in environments with very limited CPU and memory resources.

To obtain a copy of the entire article, click on the link below.
http://www.igi-global.com/articles/details.asp?ID=8239

PAPER FOUR:

“A Reservation-based Extended Transaction Protocol for Coordination of Web Services”

Zhao, Wenbing; Kart, Firat; Moser, L.E.; Melliar-Smith, P.M.

Web services can be used to automate business activities that span multiple enterprises over the Internet. Such business activities require a coordination protocol to reach consistent results among the participants in the business activity. In the current state of the art, either classical distributed transactions or extended transactions with compensating transactions are used. However, classical distributed transactions lock data in the databases of different enterprises for unacceptable durations or involve repeated retries, and compensating transactions can lead to inconsistencies in the databases of the different enterprises. In this article, we describe a novel reservation protocol that can be used to coordinate the tasks of a business activity. Instead of resorting to compensating transactions, the reservation protocol employs an explicit reservation phase and an explicit confirmation and cancellation phase. We show how our reservation protocol maps to the Web services coordination specification, and describe our implementation of the reservation protocol. We compare the performance of the reservation protocol with that of the two-phase commit protocol and optimistic two-phase commit protocol. We also compare the probability of inconsistency for the reservation protocol with that for compensating transactions.

To obtain a copy of the entire article, click on the link below.
http://www.igi-global.com/articles/details.asp?ID=8240

PAPER FIVE:

“DsCWeaver: Synchronization-Constraint Aspect Extension to Procedural Process Specification Languages”

Wu, Qinyi; Pu, Calton; Sahai, Akhil; Barga, Roger

Correct synchronization among activities is critical in a business process. Current process languages such as BPEL specify the control flow of processes procedurally, which can lead to inflexible and tangled code for managing a crosscutting aspect? synchronization constraints that define permissible sequences of execution for activities. In this article, we present DSCWeaver, a tool that enables a synchronization-aspect extension to procedural languages. It uses DSCL (directed-acyclic-graph synchronization constraint language) to achieve three desirable properties for synchronization modeling: fine granularity, declarative syntax, and validation support. DSCWeaver then automatically generates executable code for synchronization. We demonstrate the advantages of our approach in a service deployment process written in BPEL and evaluate its performance using two metrics: lines of code (LoC) and places to visit (PtV). Evaluation results show that our approach can effectively reduce the development effort of process programmers while providing performance competitive to unwoven BPEL code.

To obtain a copy of the entire article, click on the link below.
http://www.igi-global.com/articles/details.asp?ID=8241

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For full copies of the above articles, check for this issue of the International Journal of Web Services Research (JWSR) in your Institution's library.
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