This article is an editorial note submitted to CCR. It has NOT been peer reviewed. The author takes full responsibility for this article’s technical content. Comments can be posted through CCR Online. This paper discusses the concept of Cloud Computing to achieve a complete definition of what a Cloud is, using the main characteristics typically associated with this paradigm in the literature. More than 20 definitions have been studied allowing for the extraction of a consensus definition as well as a minimum definition containing the essential characteristics. This paper pays much attention to the Grid paradigm, as it is often confused with Cloud technologies. We also describe the relationships and distinctions between the Grid and Cloud approaches. Categories and Subject Descriptors

Abstract. Depending on whether the users or the providers are performing it, Identity Management (IM) traditionally has different meanings. For users, IM means to choose between one’s own identities and roles, in order to make selected personal information available to providers under privacy aspects. For providers, IM typically consists of centralized identity data repositories and their use by the offered services. Methods and tools for both aspects of IM have developed almost orthogonally, failing to consider their interoperability and complementary purposes. We analyze the similarities between both IM aspects and demonstrate how both sides can benefit from the use of a common policy language for personal information release and service provisioning. We derive criteria for this common policy language, demonstrate XACML’s suitability and discuss our prototype for the Shibboleth IM system. 1