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		| Paper: | 
		Group Membership Based Authorization to CADC Resources | 
	 
	
		| Volume: | 
		461, Astronomical Data Analysis Software and Systems XXI | 
	 
	
		| Page: | 
		311 | 
	 
	
		| Authors: | 
		Damian, A.; Dowler, P.; Gaudet, S.; Hill, N. | 
	 
	
	
		| Abstract: | 
		The Group Membership Service (GMS), implemented at the Canadian Astronomy Data
 Centre (CADC), is a prototype of what could eventually be an IVOA standard for a
 distributed and interoperable group membership protocol. 
 
 Group membership is the
 core authorization concept that enables teamwork and collaboration amongst
 astronomers accessing distributed resources and services. The service integrates
 and complements other access control related IVOA standards such as
 single-sign-on (SSO) using X.509 proxy certificates and the Credential
 Delegation Protocol (CDP).
 The GMS has been used at CADC for several years now, initially as a subsystem
 and then as a stand-alone Web service. It is part of the authorization mechanism
 for controlling the access to restricted Web resources as well as the VOSpace
 service hosted by the CADC. We present the role that GMS plays within the access
 control system at the CADC, including the functionality of the service and how
 the different CADC services make use of it to assert user authorization to
 resources. We also describe the main advantages and challenges of using the
 service as well as future work to increase its robustness and
 functionality. | 
	 
	
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