CISPA
Browse

BUFFing signature schemes beyond unforgeability and the case of post-quantum signatures

Download (735.18 kB)
conference contribution
posted on 2023-11-29, 18:16 authored by Cas CremersCas Cremers, Samed Düzlü, Rune Fiedler, Marc Fischlin, Christian Janson
Modern digital signature schemes can provide more guarantees than the standard notion of(strong) unforgeability, such as offering security even in the presence of maliciously generated keys, or requiring to know a message to produce a signature for it. The use of signature schemes that lack these properties has previously enabled attacks on real-world protocols. In this work we revisit several of these notions beyond unforgeability, establish relations among them, provide the first formal definition of nonre-signability, and a transformation that can provide these properties for a given signature scheme in a provable and efficient way.Our results are not only relevant for established schemes: for example, the ongoing NIST PQC competition towards standardizing post-quantum signature schemes has six finalists in its third round. We perform an in-depth analysis of the candidates with respect to their security properties beyond unforgeability. We show that many of them do not yet offer these stronger guarantees, which implies that the security guarantees of these post-quantum schemes are not strictly stronger than, but instead incomparable to, classical signature schemes. We show how applying our transformation would efficiently solve this,paving the way for the standardized schemes to provide these additional guarantees and thereby making them harder to misuse.

History

Preferred Citation

Cas Cremers, Samed Düzlü, Rune Fiedler, Marc Fischlin and Christian Janson. BUFFing signature schemes beyond unforgeability and the case of post-quantum signatures. In: IEEE Symposium on Security and Privacy (S&P). 2021.

Primary Research Area

  • Reliable Security Guarantees

Name of Conference

IEEE Symposium on Security and Privacy (S&P)

Legacy Posted Date

2021-05-10

Open Access Type

  • Unknown

BibTeX

@inproceedings{cispa_all_3417, title = "BUFFing signature schemes beyond unforgeability and the case of post-quantum signatures", author = "Cremers, Cas and Düzlü, Samed and Fiedler, Rune and Fischlin, Marc and Janson, Christian", booktitle="{IEEE Symposium on Security and Privacy (S&P)}", year="2021", }

Usage metrics

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC