---
res:
  bibo_abstract:
  - "We introduce a new primitive, called beholder signatures (Full version [14] of
    the paper is available at https://eprint.iacr.org/2025/1900), which, in some sense,
    are the opposite of blind signatures. In a beholder signature, one signs a commitment
    to a (potentially very long) message, and the signature attests that the parties
    participating in the signing process, who know the secret key, jointly also know
    the entire committed message. This guarantee holds even against distributed adversaries
    that use secure multi-party computation (MPC) to produce the signature. We work
    in the distributed adversarial model (Dziembowski, Faust, and Lizurej, Crypto’23),
    where one assumes that it is infeasible to evaluate a large number of hash queries
    without any of the participating parties learning the input. We propose a construction
    of beholder signatures in the random oracle model. The starting point of our construction
    is proofs of complete knowledge, recently proposed by (Kelkar et al. CCS’24),
    which build on Fischlin’s transformation of a sigma protocol to a non-interactive,
    straight-line extractable zero-knowledge proof of knowledge. Our scheme is concretely
    efficient and comes with a proof-of-concept implementation using Schnorr as the
    underlying sigma protocol.\r\n\r\nThe primary applications of beholder signatures
    can be found within the blockchain space. In particular, we describe how to use
    them to construct proofs of custody (Feist, 2021) that do not require ephemeral
    keys and are non-interactive. We also outline applications to data dissemination,
    data availability, and proofs of replication.@eng"
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Stefan
      foaf_name: Dziembowski, Stefan
      foaf_surname: Dziembowski
  - foaf_Person:
      foaf_givenName: Sebastian
      foaf_name: Faust, Sebastian
      foaf_surname: Faust
  - foaf_Person:
      foaf_givenName: Paweł
      foaf_name: Kedzior, Paweł
      foaf_surname: Kedzior
  - foaf_Person:
      foaf_givenName: Marcin
      foaf_name: Mielniczuk, Marcin
      foaf_surname: Mielniczuk
  - foaf_Person:
      foaf_givenName: Susil Kumar
      foaf_name: Mohanty, Susil Kumar
      foaf_surname: Mohanty
  - foaf_Person:
      foaf_givenName: Krzysztof Z
      foaf_name: Pietrzak, Krzysztof Z
      foaf_surname: Pietrzak
      foaf_workInfoHomepage: http://www.librecat.org/personId=3E04A7AA-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0002-9139-1654
  bibo_doi: 10.1007/978-3-032-35374-0_5
  bibo_volume: 16801
  dct_date: 2026^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0302-9743
  - http://id.crossref.org/issn/1611-3349
  - http://id.crossref.org/issn/9783032353733
  dct_language: eng
  dct_publisher: Springer@
  dct_title: Beholder signatures@
...