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
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
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- 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
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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