http://dl.gi.de/handle/20.500.12116/23 2026-07-21T13:03:14Z http://dl.gi.de/handle/20.500.12116/41696 A shared responsibility model to support cross border and cross organizational federation on top of decentralized and self-sovereign identity: Architecture and first PoC Kubach, Michael; Henderson, Isaac; Bithin, Alangot; Dimitrakos, Theo; Vargas, Juan; Winterstetter, Matthias; Krontiris, Ioannis Roßnagel, Heiko; Schunck, Christian H.; Günther, Jochen This paper discusses the challenges of transitioning from legacy federated identity systems to emerging decentralized identity technologies based on self-sovereign identities (SSI) and verifiable credentials, which are being used in initiatives such as Gaia-X and Catena-X for secure and sovereign data sharing. The adoption of SSI and decentralized identity technologies requires a standardized reference model that addresses challenges around trust in cross-border and crossorganizational federations based on decentralized identities. To facilitate this transition, the paper proposes a new Fed2SSI architecture that introduces a middle layer of abstraction for the policybased transformation of credentials, enabling interoperability between legacy federated identity solutions and SSI/decentralized identity environments. The architecture is implemented in a prototype and an exemplary use case is presented to illustrate the added value of this approach. 2023-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/41697 The possible impact s of the eIDAS 2.0 digital identity approach in Germany and Europe Schwalm, Steffen Roßnagel, Heiko; Schunck, Christian H.; Günther, Jochen eIDAS 2.0 introduces the EU Digital Wallet as the eID mean including not only the PID (eID Scheme) but also additional attributes like (qualified) attestation of attributes and gives the control over its identity back to the user in regulated approach. This means that eIDAS 2.0 gives the possibility to provide legal trust on decentralized digital identities in self-sovereign manner by combining existing trust model from eIDAS 1.0 with SSI-approach. The paper describes based on the legal proposal possible impacts of eIDAS 2.0 on German and European identity and trust services in order to provide framework for trustworthy digital transactions in EU and EFTA 2023-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/41694 A more User-Friendly Digital Wallet? User Scenarios of a Future Wallet Krauß, Anna-Magdalena; Kostic, Sandra; Sellung, Rachelle A. Roßnagel, Heiko; Schunck, Christian H.; Günther, Jochen Identity wallets enable the management and use of digital identities and verification documents stored in one app. Users manage their data independently and decide for themselves which data they want to disclose for identification purposes. Recent research shows that current digital wallets face many usability problems, which makes it difficult for users to grasp their concept and how to use them. This paper presents an enhanced concept of a wallet, where its functionality is presented with user scenarios that have a user centric approach. The user scenarios illustrate a variety of possible uses of the wallet. For example, the new wallet concept envisions, how data can be transferred from one wallet to another person's wallet, how data can be managed by different people in one wallet, or how only individual pieces of information from credentials can be shared to maintain greater privacy for users. 2023-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/41695 Modeling the Threats to Self-Sovereign Identities Pöhn, Daniela; Grabatin, Michael; Hommel, Wolfgang Roßnagel, Heiko; Schunck, Christian H.; Günther, Jochen Self-sovereign identity (SSI) is a relatively young identity management paradigm allowing digital identities to be managed in a user-centric, decentralized manner, often but not necessarily utilizing distributed ledger technologies. This emerging technology gets into the focus through the new electronic IDentification, Authentication and trust Services (eIDAS) regulation in Europe. As identity management involves the management and use of personally identifiable information, it is important to evaluate the threats to SSI. We apply the STRIDE (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, and Elevation of Privilege) threat modeling approach to the core components of SSI architecture and the interactions between them. Based on the summarized results, we discuss relevant mitigation methods and future research areas. 2023-01-01T00:00:00Z