{"oa_version":"Preprint","alternative_title":["LNCS"],"publication_identifier":{"issn":["0302-9743"],"eissn":["1611-3349"],"isbn":["9783032122896"]},"publication":"23rd International Conference on Theory of Cryptography","article_processing_charge":"No","OA_type":"green","page":"171-202","type":"conference","status":"public","title":"Space-deniable proofs","day":"05","date_created":"2025-12-21T23:01:33Z","publisher":"Springer Nature","main_file_link":[{"open_access":"1","url":"https://eprint.iacr.org/2025/1723"}],"project":[{"grant_number":"F8509","name":"Security and Privacy by Design for Complex Systems","_id":"34a34d57-11ca-11ed-8bc3-a2688a8724e1"}],"corr_author":"1","author":[{"full_name":"Dujmovic, Jesko","last_name":"Dujmovic","first_name":"Jesko"},{"first_name":"Christoph Ullrich","last_name":"Günther","id":"ec98511c-eb8e-11eb-b029-edd25d7271a1","full_name":"Günther, Christoph Ullrich"},{"last_name":"Pietrzak","first_name":"Krzysztof Z","full_name":"Pietrzak, Krzysztof Z","orcid":"0000-0002-9139-1654","id":"3E04A7AA-F248-11E8-B48F-1D18A9856A87"}],"_id":"20844","intvolume":"     16271","quality_controlled":"1","date_updated":"2025-12-29T11:44:16Z","abstract":[{"lang":"eng","text":"We introduce and construct a new proof system called Non-interactive Arguments of Knowledge or Space (NArKoS), where a space-bounded prover can convince a verifier they know a secret, while having access to sufficient space allows one to forge indistinguishable proofs without the secret.\r\nAn application of NArKoS are space-deniable proofs, which are proofs of knowledge (say for authentication in access control) that are sound when executed by a lightweight device like a smart-card or an RFID chip that cannot have much storage, but are deniable (in the strong sense of online deniability) as the verifier, like a card reader, can efficiently forge such proofs.\r\nWe construct NArKoS in the random oracle model using an OR-proof combining a sigma protocol (for the proof of knowledge of the secret) with a new proof system called simulatable Proof of Transient Space (simPoTS). We give two different constructions of simPoTS, one based on labelling graphs with high pebbling complexity, a technique used in the construction of memory-hard functions and proofs of space, and a more practical construction based on the verifiable space-hard functions from TCC’24 where a prover must compute a root of a sparse polynomial. In both cases, the main challenge is making the proofs efficiently simulatable."}],"doi":"10.1007/978-3-032-12290-2_6","year":"2025","scopus_import":"1","conference":{"start_date":"2025-12-01","location":"Aarhus, Denmark","end_date":"2025-12-05","name":"TCC: Theory of Cryptography"},"citation":{"mla":"Dujmovic, Jesko, et al. “Space-Deniable Proofs.” <i>23rd International Conference on Theory of Cryptography</i>, vol. 16271, Springer Nature, 2025, pp. 171–202, doi:<a href=\"https://doi.org/10.1007/978-3-032-12290-2_6\">10.1007/978-3-032-12290-2_6</a>.","short":"J. Dujmovic, C.U. Günther, K.Z. Pietrzak, in:, 23rd International Conference on Theory of Cryptography, Springer Nature, 2025, pp. 171–202.","ama":"Dujmovic J, Günther CU, Pietrzak KZ. Space-deniable proofs. In: <i>23rd International Conference on Theory of Cryptography</i>. Vol 16271. Springer Nature; 2025:171-202. doi:<a href=\"https://doi.org/10.1007/978-3-032-12290-2_6\">10.1007/978-3-032-12290-2_6</a>","chicago":"Dujmovic, Jesko, Christoph Ullrich Günther, and Krzysztof Z Pietrzak. “Space-Deniable Proofs.” In <i>23rd International Conference on Theory of Cryptography</i>, 16271:171–202. Springer Nature, 2025. <a href=\"https://doi.org/10.1007/978-3-032-12290-2_6\">https://doi.org/10.1007/978-3-032-12290-2_6</a>.","ieee":"J. Dujmovic, C. U. Günther, and K. Z. Pietrzak, “Space-deniable proofs,” in <i>23rd International Conference on Theory of Cryptography</i>, Aarhus, Denmark, 2025, vol. 16271, pp. 171–202.","ista":"Dujmovic J, Günther CU, Pietrzak KZ. 2025. Space-deniable proofs. 23rd International Conference on Theory of Cryptography. TCC: Theory of Cryptography, LNCS, vol. 16271, 171–202.","apa":"Dujmovic, J., Günther, C. U., &#38; Pietrzak, K. Z. (2025). Space-deniable proofs. In <i>23rd International Conference on Theory of Cryptography</i> (Vol. 16271, pp. 171–202). Aarhus, Denmark: Springer Nature. <a href=\"https://doi.org/10.1007/978-3-032-12290-2_6\">https://doi.org/10.1007/978-3-032-12290-2_6</a>"},"acknowledgement":"Jesko Dujmovic: Funded by the European Union (ERC, LACONIC, 101041207). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.\r\nChristoph U. Günther and Krzysztof Pietrzak: This research was funded in whole or in part by the Austrian Science Fund (FWF) 10.55776/F85. For open access purposes, the author has applied a CC BY public copyright license to any author-accepted manuscript version arising from this submission.","oa":1,"month":"12","publication_status":"published","language":[{"iso":"eng"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","department":[{"_id":"KrPi"}],"OA_place":"repository","date_published":"2025-12-05T00:00:00Z","volume":16271}