September 16, 2025, 10:00 am Science Building (SE-43), room 215
Speaker: Dung Bui, LIP6, Sorbonne Université, France
Title: FOLEAGE: F4OLE-Based Multi-Party Computation for Boolean Circuits FLYER
Abstract: Secure Multi-party Computation (MPC) allows two or more parties to compute any public function over their privately-held inputs, without revealing any information beyond the result of the computation. Modern protocols for MPC generate a large amount of input-independent preprocessing material called multiplication triples, in an offline phase. This preprocessing can later be used by the parties to efficiently instantiate an input-dependent online phase computing the function.
To date, the state-of-the-art secure multi-party computation protocols in the preprocessing model are tailored to secure computation of arithmetic circuits over large fields and require little communication in the preprocessing phase, typically O(N · m) to generate m triples among N parties. In contrast, when it comes to computing preprocessing for computations that are naturally represented as Boolean circuits, the state-of-the-art techniques have not evolved since the 1980s, and in particular, require every pair of parties to execute a large number of oblivious transfers before interacting to convert them to N-party triples, which induces an Ω(N^2 · m) communication overhead.
In this paper, we introduce FOLEAGE, which addresses this gap by introducing an efficient preprocessing protocol tailored to Boolean circuits. FOLEAGE exhibits excellent performance: It generates m multiplication triples over F2 using only N · m + O(N^2 · log m) bits of communication for N-parties, and can concretely produce over 12 million triples per second in the 2-party setting on one core of a commodity machine. Our result builds upon an efficient Pseudorandom Correlation Generator (PCG) for multiplication triples over the field F4. Roughly speaking, a PCG enables parties to stretch a short seed into a large number of pseudorandom correlations non-interactively, which greatly improves the efficiency of the offline phase in MPC protocols. Our construction significantly outperforms the state-of-the-art, which we demonstrate via a prototype implementation. This is achieved by introducing a number of protocol-level, algorithmic-level, and implementation-level optimizations on the recent PCG construction of Bombar et al. (Crypto 2023) from the Quasi-Abelian Syndrome Decoding assumption.
Bio: Dung Bui is a postdoctoral researcher at LIP6, Sorbonne Université, France. She completed her PhD at IRIF, Université Paris Cité. Her research interests are in various aspects of both practical and theoretical cryptography, including secure multiparty computation, zero-knowledge proofs, and post-quantum cryptography.
Contact email: dung.bui@lip6.fr
Speaker: Nurdaulet Shynarbek, Mathematics Educational Program Coordinator (In-person)
Title: Novel Representations of log 2 Through Polynomial Continued Fractions FLYER
Abstract: This presentation explores new representations of the mathematical constant log 2 using polynomial continued fractions. Building on previous work in continued fraction theory, we investigate a conjecture by Zhu He which proposes a specific polynomial continued fraction for log 2. We will demonstrate the validity of this conjecture and introduce an infinite family of new polynomial continued fractions for log 2.
September 9, 2025, 11:00 am Science Building (SE-43), room 215
Speaker: Alibek Orynbassar, Senior Lecturer, Department of Pedagogy of Natural Sciences, SDU University
Title: Complete Classification of Quadratic Irrationals with Period Two FLYER
Abstract: This talk presents a full classification of quadratic irrationals whose continued fraction expansions have period length two. While it is known that the continued fraction of N is periodic, the distribution of period lengths is less understood. We establish precise conditions for the period-two case and illustrate the results with numerical examples.
Bio: Alibek Orynbassar is a Senior Lecturer in the Department of Pedagogy of Natural Sciences at SDU University in Kaskelen, Kazakhstan, a position he has held since July 2023. He is currently pursuing a PhD in Mathematics and Natural Sciences at SDU.
He earned both his Master’s (2017) and Bachelor’s (2014) degrees in Mathematics and Natural Sciences from SDU. From July 2022 to June 2023, he was a Visiting Scholar at Teachers College, Columbia University, where he expanded his expertise in mathematics education and research.
Prior to his current role, he served as Mathematics Program Coordinator in the Department of Education at SDU (2020–2022) and as Senior Lecturer (2017–2022). Earlier in his career, he taught mathematics in secondary schools (2013–2017), where he prepared students for mathematics Olympiads. He has also contributed as a jury member for regional school mathematics Olympiads and scientific project competitions (2018–2020).
September 2, 2025, 10:00 am Science Building (SE-43), room 215
Speaker: Hansraj Jangir, Ph.D. student, Florida Atlantic University
Title: A Quasi-polynomial time Quantum Algorithm for the Extrapolated Dihedral Coset Problem. FLYER
Abstract: The Learning With Errors (LWE) problem, introduced by Regev (STOC’05), is one of the fundamental problems in lattice-based cryptography, believed to be hard even for quantum adversaries. Regev (FOCS’02) showed that LWE reduces to the quantum Dihedral Coset Problem (DCP) and later, Brakerski et al. (PKC 2018) extended this to the more general Extrapolated Dihedral Coset Problem (EDCP). In this talk, we present a quasi-polynomial time quantum algorithm for solving EDCP over power-of-two moduli, using a quasi-polynomial number of samples. We stress that our algorithm does not affect the security of LWE with standard parameters, as the reduction from standard LWE to EDCP limits the number of samples to be polynomial.
Bio: Hansraj is a PhD student in the Department of Mathematics and Statistics at Florida Atlantic University, Boca Raton. Prior to starting his doctoral studies, he worked as a Junior Research Fellow at the Defense Research and Development Organization (DRDO), Delhi. His research interests include lattice based cryptography and quantum algorithms.
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