Anonymous credential systems [8, 9, 12, 24] allow anonymous yet authenticated and
accountable transactions between users and service providers. As such, they represent a …

Protecting rights over relational data is of ever increasing interest, especially considering
areas where sensitive, valuable content is to be outsourced. A good example is a data …

Distributed software subjects face the problem of determining one another's trustworthiness.
The problem considered is managing the exchange of credentials between strangers for the …

We address the problem of authorization in large-scale, open, distributed systems.
Authorization decisions are needed in electronic commerce, mobile-code execution, remote …

Despite considerable advancements in the area of access control and authorization
languages, current approaches to enforcing access control are all based on monolithic and …

The Internet enables connectivity between many strangers: entities that don't know each
other. We present the Trust Policy Language (TPL), used to define the mapping of strangers …

Delegation is the process whereby an active entity in a distributed environment authorizes
another entity to access resources. In today's distributed systems, a user often needs to act …

The widespread use of Internet-based services is increasing the amount of information (such
as user profiles) that clients are required to disclose. This information demand is necessary …

In this paper, we consider the influence of trust on the assimilation of acquired information
into an agent's belief. By use of modal logic, we semantically and axiomatically characterize …

We address why, and especially how, to represent business rules in e-commerce contracts.
By contracts, we mean descriptions of goods and services offered or sought, including …