Our regular Crypto Café seminars take place every other Tuesday,10 am-10:50 am during the semester. We invite local and international experts on topics in Mathematics and Computer Science related to Cryptography and Information Security.
Come and join us for freshly brewed coffee and interesting conversations on the most exciting topics in cryptography.
Where: SE-43 (Charles E. Schmidt College of Science) - Room 215
https://researchseminars.org/seminar/CryptoCafe
You can catch up on any missed meetings by following the link below:
Fall 2026, Crypto Cafe Schedule:
October 13, 2026 10:00 am Science Building (SE-43), room 215
Speaker: Yuhao Liu, Florida Atlantic University
Title: Gröbner Basis and Relinearization Algorithm for Ring-LWE +Zoom (click here)
Abstract: \textbf{Abstract.} We analyze the Gr\"obner basis attack on the Arora--Ge system \cite{AroraG11} arising from Ring-LWE samples over \[ \mathcal{R}_q = \mathbb{F}_q[X]/(X^n+1), \] with $n$ a power of two and errors bounded by $b$. We show that, with high probability over the sampled public polynomials, the highest-degree components of the resulting polynomial system span the full space of forms of degree $k$ (where $k = 2b + 1$), so that the system is semi-regular with degree of regularity $k$. Furthermore, we quantify the failure probability through a factorization of the degree-$k$ Macaulay determinant into $n$ blocks indexed by the frequencies of a negacyclic Fourier transform and permuted by Frobenius. We further show that this structure block-diagonalizes the dominant part of the linearized system and reduces the cost of the attack from \[ \Theta\!\left(n^{k\omega}\right) \] to \[ \Theta\!\left(n^{(k-1)\omega+1}\right) \] arithmetic operations in the splitting field of $X^n+1$, a saving of a factor $n^{\omega-1}$ over the corresponding unstructured computation. For ternary errors, this yields the complexity reduction \[ \Theta(n^{9}) \rightarrow \Theta(n^{7}) \] for $\omega = 3$.
Bio: Yuhao Liu is a PhD student in the department of Mathematics and Statistics, Florida Atlantic University
_____________________________________________________________________________________________________________________________________________________________
September 29, 2026 10:00 am Science Building (SE-43), room 215
Speaker: Edoardo Persichetti, Professor in the Department of Mathematics and Statistics, Florida Atlantic University
Title: A Brief Introduction to Code-Based Cryptography
Abstract: Code-based cryptography is one of the major players in the post-quantum landscape, providing solutions against attackers equipped with quantum capabilities. “In this talk, I will provide an overview of the history and main features of this area, starting with McEliece’s seminal work and progressing through modern day’s renditions and new cryptographic standards. Everyone welcome!"
Bio: Edoardo Persichetti is Professor in the Department of Mathematics and Statistics at FAU. His work in code-based cryptography spans nearly two decades and has earned him considerable recognition. He is author of many published articles in main cryptographic venues, as well as an upcoming book on the topic; he has served on numerous program committees and editorial boards, and he currently sits on the IACR board of directors. He is author of two cryptographic standards, and his expertise is often sought after in various circumstances.
September 15, 2026 10:00 am Science Building (SE-43), room 215
Speaker: Hoai Nam Le
Title: Optimal Bucket Set Construction for Multi-scalar Multiplication with Endomorphisms
Abstract: Multi-scalar multiplication (MSM), which computes a linear combination of elliptic-curve points of the form \sum_i a_iP_i, is a major computational bottleneck in many modern cryptographic protocols, particularly in proof systems. In 2023, Luo, Fu, and Gong (LFG) introduced a framework for accelerating MSM using a bucket set together with a multiplier set, allowing a trade-off between storage and online computation. In 2025, Fan, Sica, Kuchta, and Xu (FKSX) applied the LFG framework to efficient endomorphisms, exploiting units that can be applied essentially on the fly. This raises a natural optimization problem: Can we minimize the bucket size while still admitting an efficient Hamiltonian path for bucket accumulation?
In this talk, I will present our construction from a geometric viewpoint over the Eisenstein integers. I will show how this viewpoint leads to an optimal hexagonal bucket set and also allows us to construct an efficient Hamiltonian path for the bucket accumulation step. Moreover, we generalize the construction to larger multiplier sets, providing further time-memory trade-offs when additional storage is available.
This work will be presented at ASIACRYPT 2026 and is joint work with Professor Sica.
