A distributed access control mechanism for managing intellectual property rights in large-scale information systems

Content dissemination on the Internet is increasingly undertaken by intermediary servers, such as caches and proxies, which implement an indirect content dissemination model. The indirect model is characterized by several performance advantages that have helped reduce service time for content requests, including load distribution and bandwidth savings.;Current research efforts in indirect dissemination are concentrated on performance characteristics. In order to address concerns regarding IPR protection, this dissertation introduces a new type of policy, called a Distributed IPR Protection Policy (DIPP), which is specific to the indirect model. Such policies comprise the core for the development of a distributed content dissemination control mechanism, based on partial trust towards intermediary servers. Its major characteristic is its flexible design: a single DIPP can be separated into multiple parts that can be distributed among partially trusted intermediary servers. This distribution is based on content-author-defined trust topologies that are created through a component of the DIPP, called the Terms-and-conditions (TC) Pointer.;The introduction of the DIPP mechanism leads to another contribution of this dissertation: the development of a distributed system of intermediary servers that cooperatively enforce the proposed policies. Such a system is composed of two major components: (i) a new module within each intermediary server for processing DIPPs (called DIPP Processing Module); and (ii) a set of extensions in existing content retrieval protocols for communicating DIPP control information among intermediary servers (called the DIPP Control Information Set).;The new approaches developed in this dissertation are further explored in the realm of electronic commerce. A prototype for an information product distribution channel is implemented and the performance impact of the proposed mechanisms is evaluated.;At the same time, the indirect model creates new challenges in content management, especially in dissemination control. In fact, content authors may lose control of further dissemination of content copies located on intermediary servers. Hence, authors become increasingly concerned about possible infringements of their intellectual property rights (IPR).