We identify the trust management problem as a distinct and important component of security in network services. Aspects of the trust management problem include formulating security policies and security credentials, determining whether particular sets of credentials satisfy the relevant policies

each source. We cannot expect each user to know the trustworthiness of each source, nor would we want to assign top-down or global credibility values due to the subjective nature of trust. We tackle this problem by employing a web of trust, in which each user provides personal trust values for a small

We introduce the RT framework, a family of Rolebased Trust-management languages for representing policies and credentials in distributed authorization. RT combines the strengths of role-based access control and trustmanagement systems and is especially suitable for attributebased access control

Trust management is a form of distributed access control that allows one principal to delegate some access decisions to other principals. While this makes trust management more flexible than the access matrix model, it makes safety and security analysis more important. We show that in contrast

This paper discusses the rationale for designing a simple trust-management system for public-key infrastructures, called KeyNote.

access control in open environments is trust management. This chapter provides an overview of the most significant approaches for managing and negotiating trust between parties. We start by introducing the basic concepts on which trust management systems are built, describing their relationships

This paper presents a mathematical framework for expressing trust management systems. The framework makes it easier to understand existing systems and to compare them to one another, as well as to design new systems. The framework defines the semantics of a trust management engine via a least

for manipulating digital signatures. This paper describes the REFEREE trust management system for Web applications; REFEREE provides both a general policy-evaluation mechanism for Web clients and servers and a language for specifying trust policies. REFEREE places all trust decisions under explicit policy control

implementation can alleviate this problem. This survey is directed to an audience wishing to familiarize themselves with the field, for example to locate a research target or implement a trust management system. It concentrates on providing a general overview of the state of the art, combined with examples

We present soundness and completeness theorems for our earlier work on modeling trust management systems.