Regulating service access and information release on the Web

Driving and Monitoring Provisional Trust Negotiation with Metapolicies

“…Trust negotiation in PROTUNE is directly inspired by PAPL [4] and PeerTrust [6], that build on ideas introduced in [14]. In summary, each party (client and server) makes decisions based on a set of rules that entail decision atoms such as allow(X ), based on conditions over currently available credentials and declarations (sent by the other party) and a time-dependent state, covering the negotiation state, user profiles, etc.…”

“…PROTUNE's rule language extends two previous languages: PAPL [4], that until 2002 was one of the most complete policy languages for trust negotiation [10], and PEERTRUST [6], that supports distributed credentials and a more flexible policy protection mechanism. In detail, the main contributions of this paper are (i) A trust management language supporting general provisional-style actions (possibly user-defined), (ii) An extendible declarative metalanguage for driving decisions about request formulation, information disclosure, and distributed credential collection, (iii) A parameterized negotiation procedure, that gives a semantics to the metalanguage and provably satisfies some desirable properties for all possible metapolicies, (iv) Integrity constraints for negotiation monitoring and disclosure control, and (v) General, ontology-based techniques for importing and exporting metapolicies and for smoothly integrating language extensions (with an example based on the RT family of credential languages [7]).…”

Rule-Based Policy Representation and Reasoning for the Semantic Web

“…They are also specially designed for the Semantic Web. However, we refer the interested reader to other languages for policy based negotiations [20,21,22], which may be applied to the Semantic Web.…”

“…Protune's rule language extends two previous languages: PAPL [20], which until 2002 was one of the most complete policy languages for trust negotiation, and PeerTrust [7], which supports distributed credentials and a more flexible policy protection mechanism. In addition, the framework features a powerful declarative meta-language for driving some critical negotiation decisions, and integrity constraints for monitoring negotiations and credential disclosure.…”

“…The vocabulary of predicates occurring in the rules is partitioned into the following categories: Decision Predicates (currently supporting "allow()" which is queried by the negotiation for access control decisions and "sign()" which is used to issue statements signed by the principal owning the policy, Abbreviation Predicates (as described in [20]), Constraint Predicates (which comprise the usual equality and disequality predicates) and State Predicates (which perform decisions according to the state). State Predicates are further subdivided in State Query Predicates (which read the state without modifying it) and Provisional Predicates (which may be made true by means of associated actions that may modify the current state like e.g.…”