Alan Hartman - Trust Measurement and Management - SESERV SE Workshop June 2012

7/31/2019 Alan Hartman - Trust Measurement and Management - SESERV SE Workshop June 2012

1/18

2009 IBM Corporation

Trust Measurement and Management

Alan Hartman IBM Haifa Research Lab

20 June 2012

Open Research Issues


2/18


Agenda

Motivation

Defining Trust

Relationship between Risk and Trust

Basic Trust Management Scenario

More Complex Scenarios

2


3/18

2009 IBM Corporation3

Why measure and manage trust?

Distrust and caution are the parents of security. - BenjaminFranklin

The trust of the innocent is the liars most useful tool. -Stephen King

Trust, but verify. Ronald Reagan


4/18


Definition of trust

Trust is: An expectation about a future behaviour ofanother person depending on the degree of trustand the extent of the associated risk (Kasselbaum

Ph. D. Thesis in Sociology)

Trust is: A function with three parameters:Trust(Trustee, Trustor, ActivityOutcome), whose

value is the probability (degree of trust) thatTrustor believes that Trustee will produceActivityOutcome in the future

4


5/18


Relationship between trust and risk

Rational behavior: If the payoff is positive, then take therisk

Also rational: If the worst case is too awful, dont take the

risk5

Working Hypothesis: A decision (by the Trustor) on whether to offerthe Trustee the opportunity to participate in an Activity with theTrustor is based on both Trust and Risk

Payoffis: a measure of the expected utility to theTrustor associated with all possible outcomes of anactivity.Payoff(Trustor, Activity) = sum over all Outcomes(Trust( Trustee, Trustor, ActivityOutcome ) * Value(Outcome))


6/18


Academic Interest in Trust

SociologyWho trusts the Internet?What are the factors that influence a person to trust

interactions in cyberspace?

EconomicsWhat motivates trust and cooperation?What reputation and incentive mechanisms to promote

trust?

ManagementCreating and maintaining trust as part of leadership

Computer Science

Creating trust in computing infrastructure and services6


7/18 2009 IBM Corporation

Basic Trust Management Scenario

7

1. Build Trust

2. Shake Trust

3. Restore Trust



Building Trust

8

Trustor A trusts Trustee B to produce Outcome C with confidence level P0



ShakingTrust

An Event E occurs whichcauses P0 to decrease to P'which is below the thresholdPt determined by Trustee B

9



Trust Restoration

Trustee B takes mitigationaction M and measures newtrust level P ''

10



Basic Scenario For Trust Management

1) Initial condition: Trustor A trusts Trustee B toproduce outcome C with confidence level P0

2) Either an Event E occurs which causes P0 todecrease to P' which is below the threshold Pt

determined by Trustee B Or P0 < Pt in the firstplace

3) Loop on i:I. B takes mitigation action Mi and measures

confidence level Pi (Assume Mi are orderedin decreasing order of cost effectiveness)

II. Until Pi >= Pt, or no cost effective mitigationactions remain in the arsenal of B


12/18


Research Challenges for Trust Management

How to measure P for a given A, B, and C

How to determine an appropriate threshold Pt for agiven A, B, C

What are appropriate mitigation actions Mi for agiven A, B, C, E

How to detect and report trust breach events E

How to measure cost effectiveness of Mi

When to give up i.e. what is the law ofdiminishing returns in the context of A, B, C, E,and P0, P1, P2, ...Pi


13/18


Measuring Trustworthiness of ICT Systems

Quantifying TrustworthinessUsing Quantifiable Properties*

Dependability

Security

Performability

13 *University of Kansas, Resilinets Wiki
https://wiki.ittc.ku.edu/resilinets/Main_Pagehttps://wiki.ittc.ku.edu/resilinets/Main_Pagehttps://wiki.ittc.ku.edu/resilinets/Performabilityhttps://wiki.ittc.ku.edu/resilinets/Securityhttps://wiki.ittc.ku.edu/resilinets/Image:Disciplines-trustworthiness.pnghttps://wiki.ittc.ku.edu/resilinets/Image:Disciplines-trustworthiness.png


14/18


Measuring Trustworthiness of Individuals orOrganizations

14

Quantifiable Properties

Trustworthy actions

ObservedReported by trusted sourceEvidence

Trustworthy reputationReputation measureTrusted reputation systemMembership of trusted organizationTrusted guarantor


15/18


Mutual trust scenario

Alice trusts BigBank to maintain the integrity ofher credit card with P=99%

BigBank trusts Alice to be honest with it with

Q=95%E is an unauthorized credit card transaction

from Alice's account reported to BigBank byAlice (P'=85%, Q'=75%)

What actions should Alice and BigBank take torebuild mutual trust?

What is the protocol for mutual trustnegotiation?


16/18


B2B trust scenario

OmahaInsurance is negotiating with IBM tooutsource their health insurance claimsprocessing

Trust is held between IBM and Omaha andalso between Omaha and its customers

Event = break in to IBM office in Bangalore

Action C is contract negotiation between IBM

and Omaha


17/18


Trust me, Im a doctor

18


18/18

2009 IBM Corporation19

Documents

Alan Hartman - Trust Measurement and Management - SESERV SE Workshop June 2012