Enabling Advanced and Context-Dependent Access Control in RDF Stores

Abstract

Abstract. Semantic Web databases allow efficient storage and access to RDF statements. Applications are able to use expressive query languages in order to retrieve relevant metadata to perform different tasks. However, access to metadata may not be public to just any application or service. Instead, powerful and flexible mechanisms for protecting sets of RDF statements are required for many Semantic Web applications. Unfortunately, current RDF stores do not provide fine-grained protection. This paper fills this gap and presents a mechanism by which complex and expressive policies can be specified in order to protect access to metadata in multi-service environments.

A User Interface to Define and Adjust Policies for Dynamic User Models

“…We furthermore integrated the prototype into the Personal Reader framework (cf. Section 2) and applied AC4RDF (Abel et al, 2007) together with Protune to enforce the policies defined by the users. AC4RDF is an access control mechanism for RDF stores.…”

“…As outlined above, we utilize AC4RDF (Abel et al, 2007) together with Protune in our current implementation to enforce the policies formulated by the users via the easy-to-use editor presented in this paper. Another approach to access control for RDF data is discussed in (Dietzold and Auer, 2006), where access to RDF data is restricted by defining views, which correspond to RDF subgraphs an inquirer is allowed to access.…”

Controlling Access to RDF Graphs

“…Authors in [4] propose a specification language using graph patterns as defined in SPARQL [15]. Unlike our approach, in [4], triples are not annotated with accessibility information, but the enforcement mechanism is query-based, i.e., the policy permissions are injected in the query in order to ensure that the triples obtained are only the accessible ones. Unfortunately, the semantics of a policy are not formally defined in the paper, making impossible to check whether the algorithm used for enhancing the query is correct.…”

“…To enforce access control to an RDF repository, we advocate a framework which is repository independent, portable across platforms, and in which fine-grained access control is enforced by a component built on top of the RDF repository (as in [4]). More specifically, our contributions in this paper are: (i) a high level access control specification language for RDF graphs focusing on read-only operations; (ii) a formal definition of the language's semantics, based on the triple patterns of SPARQL [15]; (iii) an annotation-based enforcement model where each triple is automatically marked as accessible or inaccessible based on the available annotations and the access control policy; (iv) a set of dimensions that should be taken into account when defining a benchmark to evaluate the different enforcement models for access control; and (v) an implementation and experimentation of our framework for different platforms.…”

Understanding Online Communities by Using Semantic Web Technologies

“…Policy languages can be used to allow or deny access to some social resources, as well as to provide restricted access to SPARQL endpoints (Abel et al, 2007). In addition, these policies can be finely defined thanks to the amount of RDF data now available on the Web, especially social data.…”