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Distributed Approximation of Fixed-Points in Trust Structures

BRICS Report Series

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Field Value
 
Title Distributed Approximation of Fixed-Points in Trust Structures
 
Creator Krukow, Karl
Twigg, Andrew
 
Description Recently, Carbone, Nielsen and Sassone introduced the trust-structure framework; a semantic model for trust-management in global-scale distributed systems. The framework is based on the notion of trust structures; a set of ``trust-levels'' ordered by two distinct partial orderings. In the model, a unique global trust-state is defined as the least fixed-point of a collection of local policies assigning trust-levels to the entities of the system. However, the framework is a purely denotational model: it gives precise meaning to the global trust-state of a system, but without specifying a way to compute this abstract mathematical object. This paper complements q the denotational model of trust structures with operational techniques. It is shown how the least fixed-point can be computed using a simple, totally-asynchronous distributed algorithm. Two efficient protocols for approximating the least fixed-point are provided, enabling sound reasoning about the global trust-state without computing the exact fixed-point. Finally, dynamic algorithms are presented for safe reuse of information between computations, in face of dynamic trust-policy updates.
 
Publisher Aarhus University
 
Contributor —
 
Date 2015-02-11
 
Type info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
—
 
Format application/pdf
 
Identifier https://tidsskrift.dk/brics/article/view/21872
10.7146/brics.v12i6.21872
 
Source BRICS Report Series; No 6 (2005): RS-6 Distributed Approximation of Fixed-Points in Trust Structures
BRICS Report Series; No 6 (2005): RS-6 Distributed Approximation of Fixed-Points in Trust Structures
1601-5355
0909-0878
 
Language eng
 
Relation https://tidsskrift.dk/brics/article/view/21872/19299
 
Rights Copyright (c) 2015 BRICS Report Series