@inproceedings{01K805AG42XJEQZMQNFE8AZE0S,
  abstract     = {{With initiatives such as the European Digital Identity Wallet, the exchange of verifiable data via digital credentials
using digital wallets is reaching mainstream adoption. While digital wallets gain adoption and the ecosystem
grows, the flexibility and interoperability of querying verifiable data remains limited: digital credentials can
only be directly queried based on JSON keys, thus hampering support for internationalization and alternative
semantics. With this work, we present a practical approach to leverage Semantic Web technologies to combine the
expressiveness of RDF with the semantic nature of W3C’s recommended Verifiable Credentials and existing wallet
protocols like OID4VP. We leverage SPARQL queries to request specific claims within the OID4VP protocol, which
are evaluated over the combined RDF representation of the wallet credentials, to return Verifiable Presentations
that contain the requested claims using selective disclosure. We applied named graphs with blank node graph
names to ensure a uniform and globally unique connection between credentials and their corresponding claims
and proof graphs when storing credentials in a wallet’s Knowledge Graph. To retrieve which claims need to be
selectively disclosed from their original credentials, we applied an initial conversion from RDF triple predicates
to JSONPath pointers, thus currently supporting only a subset of SPARQL expressivity. Through the addition of a
SPARQL query in the OID4VP authorization flow, we enable semantically enriched query evaluation over the
stored credentials, opening the way to semantic alignment of multilingual vocabularies and similar ontologies
used in different online ecosystems. Future work is needed to improve SPARQL support to enable querying
over complex claim requirements, in terms of the query to JSONPath pointers, as well as addressing metadata
requirements for the requested claims}},
  articleno    = {{81}},
  author       = {{De Mulder, Gertjan and Dedecker, Ruben and De Meester, Ben and Colpaert, Pieter}},
  booktitle    = {{ISWC-C 2025 : Industry, Doctoral Consortium, Posters and Demos at ISWC 2025}},
  editor       = {{Celino, Irene and Hassanzadeh, Oktie and Bernstein, Abraham and Noy, Natasha and Cheng, Gong and Wang, Shenghui and Ferrada, Sebastián and Soulard, Thibaut and Kozaki, Kouji and Takeda, Hideaki and Gentile, Anna Lisa}},
  issn         = {{1613-0073}},
  language     = {{eng}},
  location     = {{Nara, Japan}},
  pages        = {{81:489--81:494}},
  publisher    = {{CEUR}},
  title        = {{Towards queryable verifiable credentials}},
  url          = {{https://ceur-ws.org/Vol-4085/paper81.pdf}},
  volume       = {{4085}},
  year         = {{2025}},
}