Dynamic Approach for Web Services Selection and Analysis of Security Protocols

Abstract

In the domain of Web Services, it is not uncommon to find redundant services that provide functionalities to the clients. Services with the same functionality can be clustered into a group of redundant services.Respectively, if a service offers different functionalities, it belongs to more than one group. Having various Web Services that are able to handle the client’s request suggests the necessity of a mechanism that selects the most appropriate Web Service at a given moment of time. This thesis presents an approach, Repository Based Web Services Selection,for dynamic service selection based on virtualization on the server side. It helps managing redundant services in a transparent manner as well as allows adding services to the system at run-time. In addition, the model assures a level of security since the consumers do not have direct access to the Web Services. This work describes different security aspects of Web Services and technologies they use and a framework to introduce a message level security to SOAP (SimpleObject Access Protocol). The purpose of the session protocol is explained along with the approach to authenticate two Web Services with each other and how to establish a shared secret session key with which they can encrypt their messages to ensure confidentiality. Various security issues that be came relevant during the design of the system and at the time of setting up the SOAP session are being addressed in this work. The analysis of the session setup process proves that an adversary cannot break the protocol by interception, alteration or by resending of messages.