Net TrustAlla Genkina, Indiana UniversityAllan Friedman, Harvard UniversityJean Camp, Indiana University

TIPPI WorkshopJune 13, 2005

Net Trust

Problem Statement

It is difficult to assess trustworthiness of a potential online transaction.

• Security and social context

• Simulation model and results

• Net Trust system design

• Preliminary usability testing results

Outline

Trust and context

Resources are often fairly easy to identify as good or bad

vs.

Trust and context

Why are good resources so hard to recognize online?

Trust and context

• Cost

• Identity

• Signaling

• Centralization

Contextual information is needed for trust to reduce complexity.

Traditional mechanisms to communicate trustworthiness

Seals

Traditional mechanisms to communicate trustworthiness

?

=

Abstracting the problem of online fraud and phishing

• Resources are typed as either good or bad• Bad resources do not exhibit strategic

behavior• Good resources have some enduring

identifier• Limited ability to discern type

Abstracting the problem of online fraud and phishing

• Resources are typed as either good or bad• Bad resources do not exhibit strategic

behavior• Good resources have some enduring

identifier• Limited ability to discern type

Claim: when the distribution of resource availability is correlated with the distribution of users, social network ties can be leveraged to provide users with information to predict type.

• Very simple model of networked actors deciding whether or not to visit resource– Network: extend Jin, Girvan & Newman (2000) to include

homophily

• Decision rule: a function of number of neighbors who have also visited that resource

Simulation Summary

• Under basic conditions, networked actors are very good at rejecting bad resources without avoiding good resources.

• A mechanism is needed to seed the network with good information.

• The network amplifies the power of individual detection abilities.

• Temporal signatures of bad resources (phishing) can be detected.

• BUT: non-savvy actors cannot achieve perfect (95%+) results without exogenous information sources.

Simulation Results Summary

Re-Embedding Trust

Alice is friend’s with Bob, and trusts Bob’s opinion

Bob likes this website

Alice has never heard of this website, but will transfer her trust for Bob to the website

Alice

Bob

Website

Net Trust Demo

Using a user’s social network (known as a buddly list) as well as user-selected centralized authorities (known as broadcasters) the Net Trust system displays meaningful information to the user so they can make an educated decision about the trustworthiness of a website.

The Net Trust Toolbar

Usability Results

Initial Usability Testing

• 25 Students

• Undergraduates/Graduates

• Informatics Department, Indiana University

Usability Results

Without Toolbar: 60% say they do not trust this site

With Toolbar: 42% say they do not trust this site

Usability Results

Without Toolbar: 52% say they do not trust this site

With Toolbar: 24% say they do not trust this site

Usability Results

Without Toolbar: 80% say they do not trust this site

With Toolbar: 76% say they do not trust this site

Usability Results

USEFUL

5.04.03.02.0

16

14

12

10

8

6

4

2

0

Std. Dev = .80

Mean = 3.8

N = 25.00

The System is Useful:

EASY

5.04.03.02.0

16

14

12

10

8

6

4

2

0

Std. Dev = .71

Mean = 3.8

N = 25.00

The System is Easy to Use:

Usability Results

Finally..

86% of participants said they would ENJOY using this system

80% of participants said they found the interface MEANINGFUL

And..

Future Work

Usability testing on signaling not to trust

Usability testing on a different demographic (next week)

Testing rating scheme

Development of “back-end”

Net Trust “Lite”

Thank you for your attention.

Questions?