Subterfuge-safe trust management for delegation of permissions in open environments

Open environments involve distributed entities interacting with each other in an open manner. Many distributed entities are unknown to each other but need to collaborate and share resources in a secure fashion. Usually resource owners alone decide who is trusted to access their resources. Since resource owners in open environments do not have a complete picture of all trusted entities, trust management frameworks are used to ensure that only authorized entities will access requested resources. Every trust management system has limitations, and the limitations can be exploited by malicious entities. One vulnerability is due to the lack of globally unique interpretation for permission specifications. This limitation means that a malicious entity which receives a permission in one domain may misuse the permission in another domain via some deceptive but apparently authorized route; this malicious behaviour is called subterfuge. This thesis develops a secure approach, Subterfuge Safe Trust Management (SSTM), that prevents subterfuge by malicious entities. SSTM employs the Subterfuge Safe Authorization Language (SSAL) which uses the idea of a local permission with a globally unique interpretation (localPermission) to resolve the misinterpretation of permissions. We model and implement SSAL with an ontology-based approach, SSALO, which provides a generic representation for knowledge related to the SSAL-based security policy. SSALO enables integration of heterogeneous security policies which is useful for secure cooperation among principals in open environments where each principal may have a different security policy with different implementation. The other advantage of an ontology-based approach is the Open World Assumption, whereby reasoning over an existing security policy is easily extended to include further security policies that might be discovered in an open distributed environment. We add two extra SSAL rules to support dynamic coalition formation and secure cooperation among coalitions. Secure federation of cloud computing platforms and secure federation of XMPP servers are presented as case studies of SSTM. The results show that SSTM provides robust accountability for the use of permissions in federation. It is also shown that SSAL is a suitable policy language to express the subterfuge-safe policy statements due to its well-defined semantics, ease of use, and integrability.

Creating religious place in Ireland: Hindu public places of worship and the Indian sculpture park

This paper examines the creation of religious place. It argues that the designation of a place as “religious” is a subjective and creative act which is dependent upon the perception and past, or memory, of the viewer. The paper focuses specifically on the creation of public places of worship by Hindu groups in the Dublin city area of Ireland and on the varied perceptions of the Indian Sculpture Park in County Wicklow. The creation of public places of worship results in places classified as “religious” due to the intention of the creator, the terminology used and the types of activities that take place in the space. This is in contrast to places such as the Indian Sculpture Park in County Wicklow which was created as a secular space but which is viewed by some Hindus as an outdoor temple due to the presence of sculptures of the Hindu deity Ganesh. Other Hindus do not view the space as having any religious significance and so its religiosity is contested. This points to the fact that the creation of religious place is a creative act of interpretation which is dependent upon the perception and past of the viewer and which changes over time.