研究成果

国際会議

  • Anonymous Credentials with Credential Redaction and Its Application to SSI-based Plug&Charge for Shared Vehicles
    著者
    K. Hatsugai, K. Asano, Y. Sawai, Y. Watanabe, and M. Iwamoto
    会議名
    ACISP 2025
    出版社
    Springer
    発行年
    2025
    To appear.
    Abstract

    Attribute-based anonymous credentials (ABC) allow users to prove possession of attributes (e.g., ages and addresses) to verifiers using credentials issued by trusted issuers. When considering applications of ABC to mobility services such as Plug&Charge, users should delegate the minimum necessary attributes from their credentials to their vehicles. However, existing ABC schemes and their variants do not support this functionality. In this paper, we introduce ABC with Credential Redaction (ABC-CR), enabling users to selectively extract certain attributes and create credentials for them. A delegatee holding these credentials can then prove possession of the extracted attributes on behalf of the original user. To construct an ABC-CR scheme, we introduce a new digital signature scheme called Unlinkable Twice-Redactable Signature (UTRS) and construct a concrete UTRS scheme from pairings. Our ABC-CR construction, based on UTRS, ensures constant communication costs for generating, delegating, and proving the credential. Evaluation results show that our ABC-CR scheme can be executed within practical time constraints.