analysing the relationship between risk and trust
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Analysing the Relationship between Risk and Trust. By Audun Jøsang and Stéphzne Lo Presti. Roadmap. Risk-Trust in Literature Measuring Risk-Trust Decision via Risk Balancing Trust and Risk Conclusion. Risk-Trust in Literature. subjectivity. uncertainty. Concept of Trust - PowerPoint PPT PresentationTRANSCRIPT
Analysing the Relationship between
Risk and TrustBy Audun Jøsang and Stéphzne Lo Presti
Roadmap• Risk-Trust in Literature•Measuring Risk-Trust• Decision via Risk• Balancing Trust and Risk
• Conclusion
Risk-Trust in Literature• Concept of Trust
• Trust is the extent to which one party is willing to depend on somebody, or something, in a given situation with a feeling of relative security, even though negative consequences are possible.
• Concept of Risk• Anticipated hazard, measurable
• Trust vs. Risk• Both difficult to scale• Both upon uncertainty and unpredictability• Relationship between them (antecedent, alternative, outcome)?
uncertaintyrisk
subjectivity
Risk-Trust in Literature• A risk-trust model by fuzzy logic [Manchala1998]• (trans_history, cost) -> trust
Measuring Risk-Trust : Decision via Risk
• Expected Utility (EU)
• : non-linear utility function of monetary value
• : risk averse• : risk seeking• : risk-neutral
• Expected Monetary Value (EV)
• : the monetary investment/bet• : the probability of the th outcome• : the gain factor of the outcome,
given
• Risk-Neutral Case()
Expected Gain
Measuring Risk-Trust : Decision via Risk• For Decision
• : probability of successful transaction• : gain factor to a successful transaction • : loss factor to a failed transaction
Measuring Risk-Trust : Decision via Risk• For Decision
• : the total capital• : fraction of the total capital
• varies in the same direction of and • E.g. • : factor moderating the influence of , or risk attitude• Low – risk-taking; high – risk-aversion;
Measuring Risk-Trust : Balancing Trust - Risk• “The outcome of the transaction depends on somebody or something
and that the relying party is uncertain about the outcome of the transaction.”• Paraphrase : the reliability of for producing a successful outcome• Reliability Trust: the trusting party’s probability estimate of success
of the transaction
Measuring Risk-Trust : Balancing Trust - Risk• Decision Trust• to normalize different between ’s reliability and the cut-off probability on an
agent’s decision surface (risk attitude), given (1) risk attitude defined by a decision surface, and (2) transaction outcome upon and •
• : decision surface• : probability producing a successful outcome, given and • : cut-off probability on for the same and
Measuring Risk-Trust : Balancing Trust - Risk• Decision Trust• (0,-1), (,0), and (1,1)• Decision trust depended on a distance between and • , trusting for the transaction• , undecided• , not trusting
ConclusionSummary• To derive a computational model
for risk-trust• Reliability trust: probability of
success of the transaction• Decision trust: considering risk
attitude, complete the notion of trust
Shortcomings:• Success of an operation is more
complex than reliability of • Behavior modelling
Thank You