Efficient Attribute Based Access Control for RESTful Services

Abstract. The popularity of REST grows more and more and so does the need for fine-grained access control for RESTful services. Attribute Based Access Control (ABAC) is a very generic concept that covers multiple different access control mechanism. XACML is an implementation of ABAC based on XML and is established as a standard mechanism. Its flexibility opens the opportunity to specify detailed security policies. But on the other hand it has some drawbacks regarding maintenance and performance when the complexity of security policies grows. Long processing times for authorization requests are the consequence in environments that require fine-grained access control. We describe how to design a security policy in a resource oriented environment so that its drawbacks are minimized. The results are faster processing times for access requests and an easy to manage concept for security policies for RESTful services

Hecate, Managing Authorization with RESTful XML

The potentials of REST offers new ways for communications between louse coupled entities featured through the Web of Things [12]. The binding of the disjunct components of this architecture creates security issues, such as the centralized authorization techniques respecting the independence of the underlying entities. This results in the question how authorization is performed respecting the flexibility of REST without any knowledge about the underlying resources. Nevertheless, possible knowledge about these resources should enable the authorization workflow to offer finer-granular permissions on substructures of the resources. With our new approach - we named Hecate- we offer a framework to assure simplified handling while keeping the potentials and flexibility of REST . We have designed an architecture based on XML with a flexible authorization mechanism on the one hand and optional resource-awareness on the other hand. The flexibility within the authorization work-flow bases on permission sets respecting the HTTP- verbs. Additional in-depth knowledge of the entity option- ally extends these permissions with resource-aware filters. Hecate offers not only great benefits because of its flexibility, but also because of the optional extensibility proved within the two reference implementations. With Hecate, we show that a centralized authorization mechanism combining independence and optional resource-based filtering extends the flexibility of REST rather than restricting it