210 likes | 337 Views
Token–based Dynamic Trust Establishment for Web Services. Zhengping Wu and Alfred C. Weaver Department of Computer Science University of Virginia March 2005. Outline. Motivation and Contributions State of the Art Trust Primitive and Selective Disclosure Trust Group and Dynamic Validation
E N D
Token–based Dynamic Trust Establishment for Web Services Zhengping Wu and Alfred C. Weaver Department of Computer Science University of Virginia March 2005
Outline • Motivation and Contributions • State of the Art • Trust Primitive and Selective Disclosure • Trust Group and Dynamic Validation • Token-based Solution for Web Service Trust Establishment • Conclusion and Future Work
Consumer Bank Enrollment Service Step 1: A consumer requests enrollment service from a bank Step 2: The bank discloses its policy P to the consumer Step 3: The consumer discloses her driver’s license to the bank Step 4: The bank grants access to the enrollment service Motivation - 1
Motivation - 2 • Need for trust relationships in web services environment • Need for security and privacy protection for sensitive information • Need for better mechanisms to address information leakage in trust establishment processes • Need for dynamic capability to keep track of changes in trust relationships
Contributions • The proposed trust establishment mechanism fully protects the requester’s privacy. • The proposed trust establishment mechanism is capable of disclosing private attributes selectively. • The proposed trust establishment mechanism allows the established trust relationship to be updated by following the changes of the service provider’s policy.
Motivation and Contributions • State of the Art • Trust Primitive and Selective Disclosure • Trust Group and Dynamic Validation • Token-based Solution for Web Service Trust Establishment • Conclusion and Future Work
State of the Art • Identity-based trust establishment mechanisms (common in e-commerce) • Role-based trust establishment mechanisms • Group-based trust establishment mechanisms
Motivation and Contributions • State of the Art • Trust Primitive and Selective Disclosure • Trust Group and Dynamic Validation • Token-based Solution for Web Service Trust Establishment • Conclusion and Future Work
Selective Disclosure • Causes of information leakage in real life trust establishment • A credential may not be used for its intended purpose • A pre-packaged credential may reveal more information than is necessary • Selective Disclosure • Use of available pre-packaged credentials • Control of information disclosure with credential holder’s will • Trust primitive
Attributes: Attribute 1 (name) Attribute 2 (ID number) Attribute 3 (gender) Attribute 4 (student/faculty/ staff status) Attribute 5 (address) Attribute 6 (token expiration) Attribute 7 (token issuer) Trust primitive 3 (dorm floor entrance) Trust primitive 2 (library checkout) Trust primitive 1 (electronic library access) Trust Primitive
Attribute Service Service provider’s security domain Requester’s security domain 2 7 8 Security Token Service Security Token Service 6 3 5 9 1 10 Requester Service Provider 4 Workflow of Negotiation Using Trust Primitives Trust Primitive
Motivation and Contributions • State of the Art • Trust Primitive and Selective Disclosure • Trust Group and Dynamic Validation • Token-based Solution for Web Service Trust Establishment • Conclusion and Future Work
Dynamic Validation • Representation of the established trust relationship • Trust group element in security token • Requirement of trust group element in policy • Same policy with same trust group name • Dynamic validation • Change of policy indicates new trust relationship • Change of policy requires revalidation of trust group element
Trust Group • Banking Customers share the same set of requirements in policy 1. • Mortgage Customers share the same set of requirements in policy 2.
Motivation and Contributions • State of the Art • Trust Primitive and Selective Disclosure • Trust Group and Dynamic Validation • Token-based Solution for Web Service Trust Establishment • Conclusion and Future Work
Security Token Service Security Token Service Attribute Service Attribute Service Web Service Provider Web Service Requester request Negotiation Engine Negotiation Engine dynamic trust (trust group) Architecture of the Solution
Motivation and Contributions • State of the Art • Trust Primitive and Selective Disclosure • Trust Group and Dynamic Validation • Token-based Solution for Web Service Trust Establishment • Conclusion and Future Work
Conclusion • The proposed trust establishment mechanism • allows the requestor to control what attributes are disclosed to the service provider • avoids disclosing more than is necessary which may happen with pre-packaged credentials • dynamically negotiates new credentials as necessary to follow changes in policy
Future work • Extension of trust primitive and trust group mechanisms • to allow privacy control during delegation • to allow privacy protection during delegation
The End Questions?