Computational Trust
Subjective logic was originally developed for the purpose of reasoning about trust in information security, such as when analysing trust structures of a PKI (Public-Key Infrastructure) [41]. Subjective logic and its application to this type of computation
- PDF / 1,437,128 Bytes
- 28 Pages / 439.37 x 666.138 pts Page_size
- 27 Downloads / 174 Views
Computational Trust
Subjective logic was originally developed for the purpose of reasoning about trust in information security, such as when analysing trust structures of a PKI (Public-Key Infrastructure) [41]. Subjective logic and its application to this type of computational trust was first proposed in 1997 [40]. The idea of computational trust was originally proposed by Marsh in 1994 [71]. A survey on trust modelling is provided in [12]. The concept of trust is to a large extent a mental and psychological phenomenon which does not correspond to a physical process that can be objectively observed and analysed. For this reason, formal trust models do not have any natural benchmark against which they can be compared and validated. There is thus no single correct formalism for computational trust, so that any formal trust model to a certain extent becomes ad hoc. Using subjective logic as a basis for computational trust is therefore just one of several possible approaches. Computational trust with subjective logic has been a thriving research topic since the first publication in 1997, with subsequent contributions by many different authors. It has the advantage of being intuitively sound and relatively simple, which is important when making practical implementations. The main SL operators used for computational trust are fusion and trust discounting. Fusion operators are described in Chapter 12. The operator for trust discounting is described in Section 14.3. Trust discounting is the operator for deriving trust or belief from transitive trust paths. Before diving into the mathematical details of trust discounting, the next section introduces the concept of trust from a philosophical perspective.
14.1 The Notion of Trust Trust is a directional relationship between two parties that can be called trustor and trustee. One must assume the trustor to be a ‘thinking entity’ in some form, meaning that it has the ability to make assessments and decisions based on received informa© Springer International Publishing Switzerland 2016 A. Jøsang, Subjective Logic, Artificial Intelligence: Foundations, Theory, and Algorithms, DOI 10.1007/978-3-319-42337-1_14
243
244
14 Computational Trust
tion and past experience. The trustee can be anything from a person, organisation or physical entity, to abstract notions such as information, propositions or a cryptographic key [39]. A trust relationship has a scope, meaning that it applies to a specific purpose or domain of action, such as ‘being authentic’ in the case of an agent’s trust in a cryptographic key, or ‘providing reliable information’ in the case of a person’s trust in the correctness of an entry in Wikipedia. The concept of trust goal is sometimes used in the literature [9] with the same meaning as trust scope. Mutual trust is when both parties trust each other with the same scope, but this is obviously only possible when both parties are cognitive entities capable of doing some form of reliability, risk and policy assessment. Trust influences the trustor’s attitudes and a
Data Loading...
