{"page":"134-165","cryptoeprintid":1,"date_updated":"2026-09-10T06:21:13Z","das_tickbox":"0","language":[{"iso":"eng"}],"main_file_link":[{"url":"https://doi.org/10.1007/978-3-032-35374-0_5","open_access":"1"}],"volume":16801,"status":"public","author":[{"last_name":"Dziembowski","full_name":"Dziembowski, Stefan","first_name":"Stefan"},{"last_name":"Faust","full_name":"Faust, Sebastian","first_name":"Sebastian"},{"last_name":"Kedzior","full_name":"Kedzior, Paweł","first_name":"Paweł"},{"full_name":"Mielniczuk, Marcin","last_name":"Mielniczuk","first_name":"Marcin"},{"first_name":"Susil Kumar","full_name":"Mohanty, Susil Kumar","last_name":"Mohanty"},{"first_name":"Krzysztof Z","last_name":"Pietrzak","full_name":"Pietrzak, Krzysztof Z","id":"3E04A7AA-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-9139-1654"}],"supplementarymaterial":"no","year":"2026","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publisher":"Springer","date_created":"2026-09-06T22:01:58Z","OA_place":"publisher","title":"Beholder signatures","article_processing_charge":"No","oa_version":"Published Version","external_id":{"cryptoeprintid":["2025/1900"]},"project":[{"grant_number":"F8509","_id":"34a34d57-11ca-11ed-8bc3-a2688a8724e1","name":"Security and Privacy by Design for Complex Systems"}],"day":"11","intvolume":"     16801","publication_status":"published","fulldoi":"https://doi.org/10.1007/978-3-032-35374-0_5","type":"conference","scopus_import":"1","doi":"10.1007/978-3-032-35374-0_5","publication_identifier":{"isbn":["9783032353733"],"eissn":["1611-3349"],"issn":["0302-9743"]},"citation":{"ama":"Dziembowski S, Faust S, Kedzior P, Mielniczuk M, Mohanty SK, Pietrzak KZ. Beholder signatures. In: <i>46th Annual International Cryptology Conference</i>. Vol 16801. Springer; 2026:134-165. doi:<a href=\"https://doi.org/10.1007/978-3-032-35374-0_5\">10.1007/978-3-032-35374-0_5</a>","ieee":"S. Dziembowski, S. Faust, P. Kedzior, M. Mielniczuk, S. K. Mohanty, and K. Z. Pietrzak, “Beholder signatures,” in <i>46th Annual International Cryptology Conference</i>, Santa Barbara, CA, United States, 2026, vol. 16801, pp. 134–165.","apa":"Dziembowski, S., Faust, S., Kedzior, P., Mielniczuk, M., Mohanty, S. K., &#38; Pietrzak, K. Z. (2026). Beholder signatures. In <i>46th Annual International Cryptology Conference</i> (Vol. 16801, pp. 134–165). Santa Barbara, CA, United States: Springer. <a href=\"https://doi.org/10.1007/978-3-032-35374-0_5\">https://doi.org/10.1007/978-3-032-35374-0_5</a>","ista":"Dziembowski S, Faust S, Kedzior P, Mielniczuk M, Mohanty SK, Pietrzak KZ. 2026. Beholder signatures. 46th Annual International Cryptology Conference. CRYPTO: International Cryptology Conference, LNCS, vol. 16801, 134–165.","short":"S. Dziembowski, S. Faust, P. Kedzior, M. Mielniczuk, S.K. Mohanty, K.Z. Pietrzak, in:, 46th Annual International Cryptology Conference, Springer, 2026, pp. 134–165.","mla":"Dziembowski, Stefan, et al. “Beholder Signatures.” <i>46th Annual International Cryptology Conference</i>, vol. 16801, Springer, 2026, pp. 134–65, doi:<a href=\"https://doi.org/10.1007/978-3-032-35374-0_5\">10.1007/978-3-032-35374-0_5</a>.","chicago":"Dziembowski, Stefan, Sebastian Faust, Paweł Kedzior, Marcin Mielniczuk, Susil Kumar Mohanty, and Krzysztof Z Pietrzak. “Beholder Signatures.” In <i>46th Annual International Cryptology Conference</i>, 16801:134–65. Springer, 2026. <a href=\"https://doi.org/10.1007/978-3-032-35374-0_5\">https://doi.org/10.1007/978-3-032-35374-0_5</a>."},"alternative_title":["LNCS"],"date_published":"2026-08-11T00:00:00Z","department":[{"_id":"KrPi"}],"abstract":[{"lang":"eng","text":"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."}],"researchdata_availability":"no","publication":"46th Annual International Cryptology Conference","quality_controlled":"1","acknowledgement":"We used generative AI for grammar, spell checking, and basic editing. This research was funded in whole or in part by the Austrian Science Fund (FWF) 10.55776/F85. This work has been partially funded by the European Research Council (ERC) under the European Union’s Horizon 2020 innovation program (grant CRYPTOLAYER-101044770), and by the European Research Council under the European Union’s Horizon 2020 innovation program (grant PROCONTRA-885666).","_id":"22820","oa":1,"month":"08","OA_type":"free access","conference":{"name":"CRYPTO: International Cryptology Conference","end_date":"2026-08-20","location":"Santa Barbara, CA, United States","start_date":"2026-08-17"}}