SOA Service Oriented Architecture
Service Oriented Architecture (SOA) is an architectural style that guides all aspects of creating and using business processes, packaged as services, throughout their lifecycle, as well as defining and provisioning the IT infrastructure that allows different applications to exchange data and participate in business processes loosely coupled from the operating systems and programming languages underlying those applications. SOA represents a model in which functionality is decomposed into distinct units (services), which can be distributed over a network and can be combined together and reused to create business applications. These services communicate with each other by passing data from one service to another, or by coordinating an activity between two or more services. The concepts of Service Oriented Architecture are often seen as built upon, and the evolution of, the older concepts of distributed computing and modular programming.
Service-oriented architecture (SOA) allows different ways to develop applications by combining services. The main premise of SOA is to erase application boundaries and technology differences. As applications are opened up, how we can combine these services securely becomes an issue. Traditionally, security models have been hardcoded into applications and when capabilities of an application are opened up for use by other applications, the security models built into each application may not be good enough.
Several emerging technologies and standards address different aspects of the problem of security in SOA. Standards such as WS-Security, SAML, WS-Trust and WS-SecurityPolicy address the security problem for SOA implementations that use Web Services. Technologies such as Application-oriented networking (AON) are addressing the problem of SOA security in the larger context as well.