How can security policies be centralized across an enterprise's set of Web applications? In particular, we examine the case of security policies for web services and for traditional websites and describe how the two can be administered and enforced together to improve both the cost of administration as well as the strength and flexibility of the security system.

Web Services and Websites: Different or the Same?
Organizations have significant investments in web-delivered applications. To date, these web systems have typically taken the form of websites serving up HTML pages accessible via web browsers. These systems include employee intranets, partner extranets, and consumer websites of infinite variety. The architecture of these sites is generally three-tier web applications backed by application servers. Access to these web applications is now often managed using an enterprise-scale web access management (WAM) system, such as CA SiteMinder WAM, for reasons of security, cost, user convenience, and ease of compliance. The WAM system controls who can access the web resources by first authenticating the user using one of many possible technologies, and then executing security policies in real-time to determine if they are entitled or authorized to use the requested web resource. Session cookies are generally used to maintain the user's login session during their visit to the organization's web property.

In contrast Web Services, a more recent innovation, involves the use of XML technology to link systems together. Many standards such as SOAP and WSDL enable web services to work across highly heterogeneous and distributed systems. Web services operate on an application-to-application basis rather than human-to-computer as in the case of a traditional website. The communications from the client to the service uses XML as the common language. This allows one application to call the services of another application over the network by sending an XML message to it.

Just as is the case with websites, web services require security policies that govern their usage and behavior. Security product categories such as the XML Gateway and broader identity-centric web services security systems have emerged in order to apply security policy to web services in a centralized way. To date, generally these web service security policies have been enforced independent of WAM-based policies used for website control, even when both types of web applications are deployed in the same organization.

Given the relative immaturity of web services deployments, it has been reasonable to operate with web services security policies and website security policies in isolation from one another. Web services security systems can deal with protecting application-to-application traffic, while separate website security products can deal with actual human beings accessing websites using browsers. However, changes in the maturity of the technology and the organizations that are using it are driving a more holistic approach to enterprise web security. This allows organizations to eliminate security silos even before they have been created.