Automatic Trust Negotiation

Presented by: Scott Hackman

1Scott Hackman – CS5204 – Operating Systems

Automatic Trust Negotiation

Reference

Trust-X: A Peer-to-Peer Framework for Trust Establishment

Elisa Bertino, Elena Ferrari, Anna Cinzia Squicciarini

Scott Hackman – CS5204 – Operating Systems 2

Automatic Trust Negotiation

What Is Trust Negotiation?

Would you give your credit card number to a website if you didn’t know who was running it?

No! The Internet is a hostile environment where identities aren’t always known. Sensitive information transfer can be dangerous under these conditions.

This paper establishes a framework to allow two parties, who may have never interacted before, to exchange information in a bilateral and incremental way to gain each other’s trust prior to divulging sensitive information.

We perform the same fundamental algorithm every day when we interact with people.

Scott Hackman – CS5204 – Operating Systems 3

Automatic Trust Negotiation

About The Paper

Trust-X: A Peer-to-Peer Framework for Trust Establishment is designed to compile work already done in this field, along with some added novel concepts by the authors, to create an implementable architecture for Trust Establishment.

Scott Hackman – CS5204 – Operating Systems 4

Automatic Trust Negotiation

ATN is NOT Encryption

Trust Negotiation is designed to work with public key encryption: Even though you may possess an x-bit key that can’t be cracked, there is no guarantee that the person, or computer, that you are interacting with is who they say they are.

Public key encryption should be used to pass data between two entities to ensure confidential data transfer; ATN verifies identity and qualification, not data security.

Scott Hackman – CS5204 – Operating Systems 5

Automatic Trust Negotiation

XML Syntax Example

Scott Hackman – CS5204 – Operating Systems 6

Automatic Trust Negotiation

Trust-X Basics

Scott Hackman – CS5204 – Operating Systems 7

Generally, interactions between two entities:Controllers (CN)Requesters (RQ)

Information that is passed:Credentials – More sensitive informationDeclarations – Less sensitive – Ex: user preferences.

Negotiation Phase:Two parties perform a back-and-forth negotiation until both parties agree on a chain of events that will get them to their goal state (DELIV). It is important to remember, that no actual data is passed during this phase (they agree when to pass credit card data in their chain, but that actual data isn’t passed yet)

Automatic Trust Negotiation

Trust-X Basics

Scott Hackman – CS5204 – Operating Systems 8

Policies:The “rules” that each entity establishes for its own protection. For example, “I won’t give an employee a rental car until I know they have a valid ID and company badge.”

Automatic Trust Negotiation

Architecture for Trust-X Negotiation

Scott Hackman – CS5204 – Operating Systems 9

Automatic Trust Negotiation

Policy Example

Scott Hackman – CS5204 – Operating Systems 10

- Employees can rent with a company badge and ID card.- Non-employees can rent with drivers license and credit card.

Automatic Trust Negotiation

Policies – Big Picture

Scott Hackman – CS5204 – Operating Systems 11

How to buildTrust.

Automatic Trust Negotiation

Negotiation Process

Scott Hackman – CS5204 – Operating Systems 12

Taken from Prof. Kafura’s PowerPoint which was modified from http://www.ccs.neu.edu/home/ahchan/wsl/symposium/bertino.ppt

Automatic Trust Negotiation

Well-formed chain

Scott Hackman – CS5204 – Operating Systems 13

How do we know a set of policies will let us achieve our goal? (Decided during negotiation)

Automatic Trust Negotiation

Negotiation Tree

A tree that traverses valid policies between the Controller and Requester until an agreement is met that goes from initial communication to DELIV state (or Fail state if none exist).

Scott Hackman – CS5204 – Operating Systems 14

Automatic Trust Negotiation

Negotiation Tree Basics

Scott Hackman – CS5204 – Operating Systems 15

Automatic Trust Negotiation

Negotiation Tree Example

Scott Hackman – CS5204 – Operating Systems 16

Automatic Trust Negotiation

Questions?

Scott Hackman – CS5204 – Operating Systems 17