Towards Domain-Specific and Privacy-Preserving Qualified eID in a User-Centric Identity Model

Unique and qualified identification is essential in numerous security-critical areas, like eGovernment, or eBusiness. Therefore, many countries have already deployed eID solutions to confirm identity information of entities and to increase trust into the identity information. Many of these confirmation solutions only support an all-or-nothing disclosure, which means that selective disclosure of single attributes is not possible. Some other work has dealt with this privacy issue by using anonymous credentials or malleable signatures. However, all of these solutions lacks in flexible generation of qualified and provable pseudonyms that based on confirmed eID information. In this paper, we propose an advanced and lightweight model for user-centric and qualified identity information that facilitates selective disclosure and domain-specific altering of single identity attributes in order to protect the citizen's privacy. We illustrate the practical applicability of our model by implementing all components as prototype applications. Finally, we evaluate our model and compare it with other approaches for selective disclosure.