@phdthesis{schanzen-2020,
  title = {Towards Self-sovereign, decentralized personal data sharing and identity
        management}, 
  author = {Schanzenbach, Martin}, 
  school = {Technische Universit{\"a}t M{\"u}nchen}, 
  year = {2020}, 
  address = {Munich}, 
  type = {Dissertation}, 
  keywords = {DNS, GNU Name System, GNUnet, privacy, ReclaimID}, 
  www_section = {Self-sovereign identity, GNUnet, GNU Name System}, 
  www_tags = {selected}, 
  www_pdf_url = {http://mediatum.ub.tum.de/?id=1545514}, 
  url = {https://bibliography.gnunet.org}, 
  abstract = {Today, identity management is a key element for commercial and private
        services on the Internet. Over the past decade, digital identities evolved away
        from decentralized, pseudonymous, user-controlled personas towards centralized,
        unabiguous identities managed at and provided through service providers. This
        development was sparked by the requirement of real identities in the context of
        electronic commerce. However, it was particularly fuelled later by the emergence
        of social media and the possibilities it provides to people in order to establish
        social connections. The following centralization of identities at a handful of
        service providers significantly improved usability and reliability of identity
        services. Those benefits come at the expense of other, arguably equally important
        areas. For users, it is privacy and the permanent threat of being tracked and
        analyzed. For service providers, it is liability and the risk of facing
        significant punishment caused by strict privacy regulations which try to
        counteract the former. In this thesis, we investigate state-of-the-art approaches
        to modern identity management. We take a look at existing standards and recent
        research in order to understand the status quo and how it can be improved. As a
        result from our research, we present the following contributions: In order to
        allow users to reclaim control over their identities and personal data, we
        propose a design for a decentralized, self-sovereign directory service. This
        service allows users to share personal data with services without the need of a
        trusted third party. Unlike existing research in this area, we propose mechanisms
        which allow users to efficiently enforce access control on their data. Further,
        we investigate how trust can be established in user-managed, self-sovereign
        identities. We propose a trust establishment mechanism through the use of secure
        name systems. It allows users and organizations to establish trust relationships
        and identity assertions without the need of centralized public key
        infrastructures (PKIs). Additionally, we show how recent advancements in the area
        of non-interactive zero-knowledge (NIZK) protocols can be leveraged in order to
        create privacy-preserving attribute-based credentials (PP-ABCs) suitable for use
        in self-sovereign identity systems including our proposed directory service. We
        provide proof of concept implementations of our designs and evaluate them to show
        that they are suitable for practical applications.}, 
}