研究成果

国際会議

  • On the Power of Interaction in Signcryption
    著者
    J. Ida, J. Shikata, and Y. Watanabe
    会議名
    ISITA 2020
    出版社
    IEEE
    発行年
    2020
    To appear.
    Abstract

    Signcryption (SC) achieves the goal with lower computational costs than simply combining public-key encryption (PKE) and digital signatures (DS). Meanwhile, at SCN 2014, Dodis and Fiore formalized interactive PKE and DS. In particular, in the interactive setting, they showed a CCA-secure PKE scheme can be constructed assuming only CPA-secure PKE schemes in a black-box manner. In this paper, we focus on SC schemes in the interactive setting (ISC for short). Specifically, we newly define a model and security notions for ISC schemes. We then propose generic constructions of ISC schemes by using CPA-secure PKE schemes rather than CCA-secure ones, whereas such a realization is unknown in the context of non-interactive SC schemes. We show that two rounds are sufficient to construct an ISC scheme from only CPA-secure PKE schemes. Furthermore, we also show the first SC scheme that can be efficiently instantiated from simple assumptions in the standard model without pairings or lattices by allowing interaction.