[{"doi":"10.1007/978-3-032-12293-3_9","scopus_import":"1","intvolume":"     16269","conference":{"name":"TCC: Theory of Cryptography","end_date":"2025-12-05","location":"Aarhus, Denmark","start_date":"2025-12-01"},"date_updated":"2025-12-29T11:51:13Z","status":"public","publication_status":"published","_id":"20845","language":[{"iso":"eng"}],"article_processing_charge":"No","OA_type":"green","type":"conference","oa_version":"Preprint","department":[{"_id":"KrPi"}],"title":"Zeroizing attacks against evasive and circular evasive LWE","page":"259-290","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","main_file_link":[{"open_access":"1","url":"https://eprint.iacr.org/2025/375"}],"publication":"23rd International Conference on Theory of Cryptography","abstract":[{"lang":"eng","text":"We develop new attacks against the Evasive LWE family of assumptions, in both the public and private-coin regime. To the best of our knowledge, ours are the first attacks against Evasive LWE in the public-coin regime, for any instantiation from the family. Our attacks are summarized below.\r\n\r\nPublic-Coin Attacks.\r\n1.The recent work by Hseih, Lin and Luo [17] constructed the first Attribute Based Encryption (ABE) for unbounded depth circuits by relying on the “circular” evasive LWE assumption. This assumption has been popularly considered as a safe, public-coin instance of Evasive LWE in contrast to its “private-coin” cousins (for instance, see [10, 11]).\r\nWe provide the first attack against this assumption, challenging the widely held belief that this is a public-coin assumption.\r\n2. We demonstrate a counter-example against vanilla public-coin evasive LWE by Wee [26] in an unnatural parameter regime. Our attack crucially relies on the error in the pre-condition being larger than the error in the post-condition, necessitating a refinement of the assumption.\r\n\r\nPrivate-Coin Attacks.\r\n1. The recent work by Agrawal, Kumari and Yamada [2] constructed the first functional encryption scheme for pseudorandom functionalities (PRFE) and extended this to obfuscation for pseudorandom functionalities (PRIO) [4] by relying on private-coin evasive LWE. We provide a new attack against the assumption stated in the first posting of their work (subsequently refined to avoid these attacks).\r\n2. The recent work by Branco et al. [8] (concurrently to [4]) provides a construction of obfuscation for pseudorandom functionalities by relying on private-coin evasive LWE. We provide a new attack against their stated assumption.\r\n3. Branco et al. [8] showed that there exist contrived, “self-referential” classes of pseudorandom functionalities for which pseudorandom obfuscation cannot exist. We extend their techniques to develop an analogous result for pseudorandom functional encryption.\r\n\r\nWhile Evasive LWE was developed to specifically avoid “zeroizing attacks”, our work shows that in certain settings, such attacks can still apply."}],"citation":{"mla":"Agrawal, Shweta, et al. “Zeroizing Attacks against Evasive and Circular Evasive LWE.” <i>23rd International Conference on Theory of Cryptography</i>, vol. 16269, Springer Nature, 2025, pp. 259–90, doi:<a href=\"https://doi.org/10.1007/978-3-032-12293-3_9\">10.1007/978-3-032-12293-3_9</a>.","ama":"Agrawal S, Modi A, Yadav A, Yamada S. Zeroizing attacks against evasive and circular evasive LWE. In: <i>23rd International Conference on Theory of Cryptography</i>. Vol 16269. Springer Nature; 2025:259-290. doi:<a href=\"https://doi.org/10.1007/978-3-032-12293-3_9\">10.1007/978-3-032-12293-3_9</a>","ista":"Agrawal S, Modi A, Yadav A, Yamada S. 2025. Zeroizing attacks against evasive and circular evasive LWE. 23rd International Conference on Theory of Cryptography. TCC: Theory of Cryptography, LNCS, vol. 16269, 259–290.","ieee":"S. Agrawal, A. Modi, A. Yadav, and S. Yamada, “Zeroizing attacks against evasive and circular evasive LWE,” in <i>23rd International Conference on Theory of Cryptography</i>, Aarhus, Denmark, 2025, vol. 16269, pp. 259–290.","apa":"Agrawal, S., Modi, A., Yadav, A., &#38; Yamada, S. (2025). Zeroizing attacks against evasive and circular evasive LWE. In <i>23rd International Conference on Theory of Cryptography</i> (Vol. 16269, pp. 259–290). Aarhus, Denmark: Springer Nature. <a href=\"https://doi.org/10.1007/978-3-032-12293-3_9\">https://doi.org/10.1007/978-3-032-12293-3_9</a>","short":"S. Agrawal, A. Modi, A. Yadav, S. Yamada, in:, 23rd International Conference on Theory of Cryptography, Springer Nature, 2025, pp. 259–290.","chicago":"Agrawal, Shweta, Anuja Modi, Anshu Yadav, and Shota Yamada. “Zeroizing Attacks against Evasive and Circular Evasive LWE.” In <i>23rd International Conference on Theory of Cryptography</i>, 16269:259–90. Springer Nature, 2025. <a href=\"https://doi.org/10.1007/978-3-032-12293-3_9\">https://doi.org/10.1007/978-3-032-12293-3_9</a>."},"publisher":"Springer Nature","acknowledgement":"We thank Rachel Lin for expressing concern about the applicability of “HJL-style” attacks [15] on the construction in [2] during a talk by the first author about [2]. This was the starting point of the investigation that led us to develop the attack in [5, Sec 4.1]. The first author also thanks Hoeteck Wee for sharing his rationale for introducing evasive LWE.\r\nThe first author is supported by the CyStar center of excellence, the VHAR faculty chair, and the C3iHub fellowship. The third author thanks Cystar, IIT Madras, for supporting a visit to IIT Madras during which the collaboration was initiated. The 4th author is partly supported by JST CREST Grant Number JPMJCR22M1.","date_published":"2025-12-05T00:00:00Z","publication_identifier":{"eissn":["1611-3349"],"isbn":["9783032122926"],"issn":["0302-9743"]},"OA_place":"repository","day":"05","year":"2025","alternative_title":["LNCS"],"date_created":"2025-12-21T23:01:33Z","volume":16269,"quality_controlled":"1","author":[{"first_name":"Shweta","last_name":"Agrawal","full_name":"Agrawal, Shweta"},{"first_name":"Anuja","last_name":"Modi","full_name":"Modi, Anuja"},{"full_name":"Yadav, Anshu","id":"dc8f1524-403e-11ee-bf07-9649ad996e21","last_name":"Yadav","first_name":"Anshu"},{"last_name":"Yamada","first_name":"Shota","full_name":"Yamada, Shota"}],"month":"12","oa":1},{"isi":1,"publisher":"Springer Nature","date_published":"2024-12-12T00:00:00Z","acknowledgement":"Ehsan Ebrahimi is supported by the Luxembourg National Research Fund under the Junior CORE project QSP (C22/IS/17272217/QSP/Ebrahimi).","external_id":{"isi":["001443889100007"]},"OA_place":"repository","publication_identifier":{"issn":["0302-9743"],"isbn":["9789819608904"],"eissn":["1611-3349"]},"main_file_link":[{"url":"https://eprint.iacr.org/2024/2078","open_access":"1"}],"publication":"30th International Conference on the Theory and Application of Cryptology and Information Security","abstract":[{"text":"A universalthresholdizer (UT), constructed from a threshold fully homomorphic encryption by Boneh et. al , Crypto 2018, is a general framework for universally thresholdizing many cryptographic schemes. However, their framework is insufficient to construct strongly secure threshold schemes, such as threshold signatures and threshold public-key encryption, etc.\r\n\r\nIn this paper, we strengthen the security definition for a universal thresholdizer and propose a scheme which satisfies our stronger security notion. Our UT scheme is an improvement of Boneh et. al ’s construction at the level of threshold fully homomorphic encryption using a key homomorphic pseudorandom function. We apply our strongly secure UT scheme to construct strongly secure threshold signatures and threshold public-key encryption.","lang":"eng"}],"citation":{"ama":"Ebrahimi E, Yadav A. Strongly secure universal thresholdizer. In: <i>30th International Conference on the Theory and Application of Cryptology and Information Security</i>. Vol 15486. Springer Nature; 2024:207-239. doi:<a href=\"https://doi.org/10.1007/978-981-96-0891-1_7\">10.1007/978-981-96-0891-1_7</a>","mla":"Ebrahimi, Ehsan, and Anshu Yadav. “Strongly Secure Universal Thresholdizer.” <i>30th International Conference on the Theory and Application of Cryptology and Information Security</i>, vol. 15486, Springer Nature, 2024, pp. 207–39, doi:<a href=\"https://doi.org/10.1007/978-981-96-0891-1_7\">10.1007/978-981-96-0891-1_7</a>.","ista":"Ebrahimi E, Yadav A. 2024. Strongly secure universal thresholdizer. 30th International Conference on the Theory and Application of Cryptology and Information Security. ASIACRYPT: Conference on the Theory and Application of Cryptology and Information Security vol. 15486, 207–239.","ieee":"E. Ebrahimi and A. Yadav, “Strongly secure universal thresholdizer,” in <i>30th International Conference on the Theory and Application of Cryptology and Information Security</i>, Kolkata, India, 2024, vol. 15486, pp. 207–239.","short":"E. Ebrahimi, A. Yadav, in:, 30th International Conference on the Theory and Application of Cryptology and Information Security, Springer Nature, 2024, pp. 207–239.","chicago":"Ebrahimi, Ehsan, and Anshu Yadav. “Strongly Secure Universal Thresholdizer.” In <i>30th International Conference on the Theory and Application of Cryptology and Information Security</i>, 15486:207–39. Springer Nature, 2024. <a href=\"https://doi.org/10.1007/978-981-96-0891-1_7\">https://doi.org/10.1007/978-981-96-0891-1_7</a>.","apa":"Ebrahimi, E., &#38; Yadav, A. (2024). Strongly secure universal thresholdizer. In <i>30th International Conference on the Theory and Application of Cryptology and Information Security</i> (Vol. 15486, pp. 207–239). Kolkata, India: Springer Nature. <a href=\"https://doi.org/10.1007/978-981-96-0891-1_7\">https://doi.org/10.1007/978-981-96-0891-1_7</a>"},"quality_controlled":"1","author":[{"full_name":"Ebrahimi, Ehsan","last_name":"Ebrahimi","first_name":"Ehsan"},{"first_name":"Anshu","last_name":"Yadav","id":"dc8f1524-403e-11ee-bf07-9649ad996e21","full_name":"Yadav, Anshu"}],"month":"12","oa":1,"day":"12","year":"2024","date_created":"2025-01-05T23:01:56Z","volume":15486,"_id":"18755","OA_type":"green","article_processing_charge":"No","language":[{"iso":"eng"}],"doi":"10.1007/978-981-96-0891-1_7","scopus_import":"1","intvolume":"     15486","conference":{"end_date":"2024-12-13","name":"ASIACRYPT: Conference on the Theory and Application of Cryptology and Information Security","start_date":"2024-12-09","location":"Kolkata, India"},"date_updated":"2025-09-09T12:00:12Z","status":"public","publication_status":"published","page":"207-239","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","type":"conference","oa_version":"Preprint","department":[{"_id":"KrPi"}],"title":"Strongly secure universal thresholdizer"}]