Brunel University Research Archive (BURA) >
College of Engineering, Design and Physical Sciences >
Dept of Computer Science >
Dept of Computer Science Theses >

Please use this identifier to cite or link to this item: http://bura.brunel.ac.uk/handle/2438/6193

Title: Towards secure web services: Performance analysis, decision making and steganography approaches
Authors: Alrouh, Bachar
Advisors: Ghinea, G
Keywords: Performance analysis
Decision making
AHP
Web services
Steganography
Publication Date: 2011
Publisher: Brunel University, School of Information Systems, Computing and Mathematics
Abstract: Web services provide a platform neutral and programming language independent technology that supports interoperable machine-to-machine interaction over a network. Clients and other systems interact with Web services using a standardised XML messaging system, such as the Simple Object Access Protocol (SOAP), typically conveyed using HTTP with an XML serialisation in conjunction with other related Web standards. Nevertheless, the idea of applications from different parties communicating together raises a security threat. The challenge of Web services security is to understand and consider the risks of securing a Web-based service depending on the existing security techniques and simultaneously follow evolving standards in order to fill the gap in Web services security. However, the performance of the security mechanisms is fraught with concerns due to additional security contents in SOAP messages, the higher number of message exchanges to establish trust, as well as the extra CPU time to process these additions. As the interaction between service providers and requesters occurs via XML-based SOAP messages, securing Web services tends to make these messages longer than they would be otherwise and consequently requires interpretation by XML parsers on both sides, which reduces the performance of Web services. The work described in this thesis can be broadly divided into three parts, the first of which is studying and comparing the performance of various security profiles applied on a Web service tested with different initial message sizes. The second part proposes a multi-criteria decision making framework to aid Web services developers and architects in selecting the best suited security profile that satisfies the different requirements of a given application during the development process in a systematic, manageable, and effective way. The proposed framework, based on the Analytical Hierarchy Process (AHP) approach, incorporates not only the security requirements, but also the performance considerations as well as the configuration constraints of these security profiles. The framework is then validated and evaluated using a scenario-driven approach to demonstrate situations where the decision making framework is used to make informed decisions to rank various security profiles in order to select the most suitable one for each scenario. Finally, the last part of this thesis develops a novel steganography method to be used for SOAP messages within Web services environments. This method is based on changing the order of XML elements according to a secret message. This method has a high imperceptibility; it leaves almost no trail because it uses the communication protocol as a cover medium, and keeps the structure and size of the SOAP message intact. The method is empirically validated using a feasible scenario so as to indicate its utility and value.
Description: This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.
URI: http://bura.brunel.ac.uk/handle/2438/6193
Appears in Collections:Brunel University Theses
Computer Science
Dept of Computer Science Theses

Files in This Item:

File Description SizeFormat
FulltextThesis.pdf2.6 MBAdobe PDFView/Open

Items in BURA are protected by copyright, with all rights reserved, unless otherwise indicated.

 


Library (c) Brunel University.    Powered By: DSpace
Send us your
Feedback. Last Updated: September 14, 2010.
Managed by:
Hassan Bhuiyan