The interconnectedness of people, services and devices is a defining aspect\nof the digital revolution, and, secure digital identities are an important\nprerequisite for secure and legally compliant information exchange. Existing\napproaches to realize a secure identity management focus on central providers\nof identities such as national authorities or online service providers. Hence,\nchanging residence or service provider often means to start over and creating\nnew identities, because procedures for data portability are missing.\nSelf-sovereign digital identities are instead created and managed by\nindividuals, and enable them to maintain their digital identities independent\nfrom residence, national eID infrastructure and market-dominating service\nproviders.\n