The role of Web Services has become an unavoidable factor for all business organizations for their day to day business transactions. These transactions are exposed to various types of threats such as Distributed Denial of Service attack(DDOS),Man in the Middle Attack and Message alteration attacks in today's network environment. Hence, this book covers how to effectively prevent all these types of attacks using Service Registration and Routing System as well as Inter-Proxy web service in Message level, Transport level and Application level. Also, This book exclusively covers the details about the permutation approach that integrates the features of Hyper Text Transfer Protocol Security (HTTPS) with Hyper Text Transfer Protocol Integrity (HTTPI). Moreover, Authentication, Authorization and Confidentiality are provided for the prevention of various attacks at communication level. Finally this book covers how to improve the Quality of Service (QoS) by evaluating various parameters such as Throughput, Response time,Scalability, Reliability and Security for dynamic Web Services.