Trust and Reputation Management in an Web-Enhanced World

1. Trust and Reputation Management in an Web-Enhanced World Zhaoyuan Zhang Email: zz2198@columbia.edu

2. Preview 1 Introduction of trust and reputation management Models for trust and reputation management 2 3 Utilization of the models

3. Why trust and reputation management?

4. Emails

5. E-Commerce

6. Cloud Computing

7. Gain knowledge about unknown web services More efficient investments REASONS Helpful in making decisions Less risks

8. Agents Trusted agent: “An entity in whom faith or belief has been placed by another entity in a given context and at a given time slot” （Chang, Elizabeth. Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Page: 28. Johns Wiley & Sons; 2006.） Trusting agent: “An entity who has faith or belief in another entity in a given context and a given time slot” （Chang, Elizabeth. Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Page: 27. Johns Wiley & Sons; 2006.）

9. Time Slot A time slot is “a period of time … defined as the breadth or duration of time over which the trust value is collected” Chang, Elizabeth. Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Page: 40. Johns Wiley & Sons; 2006

10. What is trust? Trust is “defined as the belief the trusting agent has in the service provider’s willingness and capability to deliver a mutually agreed service in a given context and in a given time slot”. (Chang, Elizabeth. Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Page: 27. Johns Wiley & Sons; 2006.)

11. Trust Recommendation Trust recommendation is “a method that helps to form a trust relationship by deriving the initial trust value, also known as reputation based on references or recommendations collected from other parties”. (Chang, Elizabeth. Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Page: 40. Johns Wiley & Sons; 2006.)

12. Models for Trust and Reputation Management Trust Models Deterministic Approach Bayesian Approach Fuzzy Approach

13. Deterministic Approach Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Page: 251. Johns Wiley & Sons; 2006.

14. Deterministic Approach • Two agents: • Trusting agent: web service user • Trusted agent: one or several third party agents • Trusted agent gives the trust recommendation • Trusting agent analyzes the trust recommendation from trusted agents • Analysis is based on a period of time

15. Bayesian Approach Bayesian Theorem Use a web service’s historical performance to predict the future performance A positive historical experience has a value of 1 Use historical trust value (history) of a web service as the condition: A negative historical experience has a value of 0

16. Fuzzy Approach • Reliability • Availability • Security Define fuzzy sets of expected results of a web service from different criteria: Use a web service’s historical performance statistics For each record of the history, compare it from each aspect with the defined result sets

17. Utilization of the models Amazon’s Mechanism “Our very best sellers have a close to 0% Negative Feedback Rate… A 0-2% negative feedback rate indicates a good performance of a seller. While a negative rate of greater than 5% means there is some problem with the business practice…The feedbacks are 12-month based…” http://www.amazon.com/gp/help/customer/display.html?nodeId=1161284&#good .

18. Amazon’s Mechanism • Historical trust statistics • Fuzzy sets indicating different levels of potential performance results • Trust value is based on a time slot • Combination of different models

19. Conclusion • Introduction of trust and reputation management • Why trust management? • Definition of trusting agents, trusted agents, time slot, trust, trust recommendations. • Models for trust and reputation management • Deterministic Approach: trust recommendation • Bayesian Approach: historical trust value statistics • Fuzzy Approach: fuzzy sets, historical trust value statistics • Utilization of the models • Combination of different models

20. References • Chang, Elizabeth. Trust and Reputation for Service-Oriented Environments Technologies for Building Business Intelligence and Consumer Confidence. Johns Wiley & Sons; 2006. • M.wojcik. H.S. Venter. J.H.P. Eloff. Trust Model Evaluation Criteria: A Detailed Analysis of Trust Evaluation. 2008 • Agudo, Isaac. Fernandez-Gago, Carmen. Lopez, Javier. A Model for Trust Metrics Analysis. • Zhu, Manling. Jin, Zhi. Trust Analysis of Web Services Based on a Trust Ontology. 2007. • Machala, Daniel. E-Commerce Trust Metrics and Models. Xeroxr Research and Technology • Receiving Amazon.com Feedbacks from Buyers. http://www.amazon.com/gp/help/customer/display.html?nodeId=1161284&#good • Nefti, Samia. Meziane, Farid. Kasiran, Khairudin. A Fuzzy Trust Model for E-Commerce. • Li, Wenjuan. Ping, Lingdi. Trust Model to Enhance Security and Interoperability of Cloud Environment. 2009 • Thrope, Sean. Modeling a Trust Cloud Context. 2010.

21. Thank You !