We introduce Delegation Logic (DL), a logic-based knowledge representation (i.e., language) that deals with authorization in large-scale, open, distributed systems. Of central importance in any system for deciding whether requests should be authorized in such a system are delegation of authority, negation of authority, and con icts between authorities. DL's approach to these issues and to the i...

At Eurocrypt 2005, Boneh, Boyen, and Goh presented a hierarchical IBE for which they claimed a novel property, called limited delegation: it is possible to give an entity a private key that restricts it from generating descendant private keys beyond some depth d; in particular, with d equal to the entity’s depth, such a key allows decryption only. In this paper, we argue that this claim is nono...

In the current conventional implementation of a routine, a parent receives the outcome of its child. A parent may be coded such that it does not use the outcome of its children, thus allowing delegation an alternative implementation of the routine. As part of its execution, such a parent can replace itself by its children. The parent thus delegates the responsibility for its outcome to its chil...

The definition of access control concepts at the modeling level is an important prerequisite for the thorough implementation and enforcement of corresponding policies and constraints in a software system. In this paper, we present an approach to provide modeling support for the delegation of roles, tasks, and duties in the context of processrelated RBAC models. The delegation model elements are...

Delegating sovereignty to international organizations (IOs) is both increasingly common and controversial. I address the sources of current controversies in three claims. First, although alleged otherwise, sovereignty is eminently divisible. From practice, indivisibility should not be a barrier to delegating to IOs. Second, it is intuitive that longer chains of delegation will be more likely to...