1. ITEC 810 Workshop Paper: A Survey of Web-based Social Network Trust
Student: Eric Wang
Supervisor: Yan Wang
Subject Coordinator: Robert Dale
5th Jun 2009

2. Agenda Trust and WBSN Trust inference in a WBSN
Survey of trust inference mechanisms
Findings and discussion
Possible area for future studies
Conclusion
Question time
Slide 2

3. Problem
How trustworthy is the opinion of a friend of my friend who I do not have direct relationship with?
How to infer trust on people I do not have direct relationship via the people I do have direct relationship?
How to accurately estimate this inferred trust without negative impact from malicious users?
Slide 3

4. Trust and WBSN Trust Web-based Social Network
Have confidence or faith in a person or a piece of information
Web-based Social Network
MySpace, Facebook, LinkedIn
Decisions are made based on trust
Which movie should I watch next weekend?
Should I buy Windows Vista or wait for Windows 7?
How can we estimate trust from someone not directly connected to me in a WBSN?
Slide 4

5. Properties of trust in a WBSN
Asymmetry
Personalisation
Transitive
Slide 5

6. Trust inference in a WBSN
Trust inference in a trust diagram
Slide 6

7. Survey of Trust Inference Mechanisms
TidalTrust
Binary Trust Algorithms
Advogato Trust Metric
Appleseed
SocialTrust
FuzzyTrust Algorithm
SUNNY
Trusted Gossip
RN-Trust
We select 5 to present here
Slide 7

8. TidalTrust Jennifer Golbeck, 2005 Simple algorithm - scalable
Generic – applicable to any WBSN
Applies two conditions to increase accuracy
Only consider the shortest path
Trust threshold limit on highly trusted neighbours
Most frequently cited and compared by others
Slide 8

9. SocialTrust James Caverlee, et al, 2008
Distinguishing relationship quality from trust
Incorporating personalised user feedback
Three components:
Current quality component
History component
Adaptation to change component
More robust against malicious attacks than PageRank from Google
Slide 9

10. FuzzyTrust Algorithm James Caverlee, et al, 2008
Fuzzy linguistic terms instead of numeric trust values
Computes trust from stronger and shorter paths
More meaningful information when there is contradictory information
Slide 10

11. Trusted Gossip Arindam Mitra and Mucumaru Maheswaran, 2007
Encourages spread of good information while restrict spam messages
Perform more than one step of trust estimation
Bayesian trust estimation
Recommender system
Three approaches on where node-level and message level filtering applied
Receiver Initiated
Sender Initiated
Using both as Hybrid
Robust against reputation distribution
Slide 11

12. RN-Trust Mohsen Taherian et al, 2008
Electrical resistance network model
Simple and generic
Scalable
Improve on weakness of TidalTrust
All paths considered, not only shortest paths
Slide 12

13. Findings and discussion
Approach of trust inference estimation
Only trust values in the shortest or strongest paths
Perform more than one step of trust estimation
Include user feedback
Fuzzy linguistic terms instead of numeric trust values
Electrical resistance model
Merits and Weaknesses
Increased accuracy
Simplicity
Scalability
Dynamic update by feedback
Robust against reputation distribution
Robust against malicious attacks
Slide 13

14. Possible topics for future studies
Further improve accuracy and precision
Develop event based trust inference algorithm
Develop context aware extensions
Other applications of inference trust
Military Intelligence
Data mining
Computing requirement
CPU process
Storage
Network
Slide 14

15. Conclusion Define trust and its properties in WBSN
Survey of existing trust inference mechanisms
Merits and weaknesses in existing trust inference mechanisms
5 possible topics for future studies
Slide 15

16. Question Time
Question from the audience
Slide 16