The paper is: "Connecting to the Cloud: Providing Single Sign-On toAmazon EC2 Applications from an On-Premises Windows Domain." Excerpt:"Users hate having multiple passwords. Help desks hate multiple passwordstoo, since users forget them. Even IT operations people hate them,because managing and synchronizing multiple passwords is expensive andproblematic. Providing single sign-on (SSO) lets users log in just once,then access many applications without needing to enter more passwords.It can also make organizations more secure by reducing the number ofpasswords that must be maintained. And for vendors of Software as aService (SaaS), SSO can make their applications more attractive by lettingusers access them with less effort...
With the emergence of cloud platforms, new SSO challenges have appeared.For example, Amazon Web Services (AWS) provides the Amazon ElasticCompute Cloud (Amazon EC2). This technology lets a customer create AmazonMachine Images (AMIs) containing an operating system, applications, andmore. The customer can then launch instances of those AMIs (virtualmachines) to run applications on the Amazon cloud. Similarly, Microsoftprovides Windows Azure, which lets customers run Windows applications onMicrosoft's cloud. When an application running on a cloud platform needsto be accessed by a user in an on-premises Windows domain, giving thatuser single sign-on makes sense. Fortunately, there are several waysto do this..."
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Courtesy:http://realworldxml.blogspot.com/2010/01/windows-domain-to-amazon-ec2-single.html