Trust Relationships in Privacy-ABCs’ Ecosystems

Abstract

— Privacy Preserving Attribute-based Credentials (Privacy-ABCs) are elegant techniques to offer strong authentication and a high level of security to the service providers, while users’ privacy is preserved. Users can obtain certified attributes in the form of Privacy-ABCs, and later derive unlinkable tokens that only reveal the necessary subset of information needed by the service providers. Therefore, Privacy-ABCs open a new way towards privacy-friendly identity management systems. In this regards, considerable effort has been made to analyse Privacy-ABCs , design a generic architecture model, and verify it in pilot environments within the ABC4Trust EU project. However, before the technology adopters try to deploy such an architecture, they would need to have a clear understanding of the required trust relationships.

In this paper, we focus on identifying the trust relationships between the involved entities in Privacy-ABCs’ ecosystems and provide a concrete answer to “who needs to trust whom on what?” In summary, nineteen trust relationships were identified, from which three of them considered to be generic trust in the correctness of the design, implementation and initialization of the crypto algorithms and the protocols. Moreover, our findings show that only six of the identified trust relationships are extra requirements compared with the case of passport documents as an example for traditional certificates.