Our regular Crypto Café seminars take place every other Thursday,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 and via Zoom
You can catch up on any missed meetings by following the below link:
Spring, 2025, Crypto Cafe Schedule: (TBA)
December 5, 2024, 10:00 am +Zoom (click here)
Speaker: Abhraneel Dutta, Ph.D., Florida Atlantic University
Title: Polynomial Inversion Algorithms in Constant Time for Post-Quantum Cryptography
Abstract: The computation of the inverse of a polynomial over a quotient ring or a finite field plays a very important role during the key generation of post-quantum cryptosystems like NTRU, BIKE, and LEDACrypt. It is therefore important that there exist an efficient algorithm capable of running in constant time, to prevent timing side-channel attacks. In this article, we study both constant-time algorithms based on Fermat's Little Theorem and the Extended GCD Algorithm, and provide a detailed comparison in terms of performance. According to our conclusion, we see that the constant-time Extended GCD-based Bernstein-Yang's algorithm shows a better performance with 1.76x-3.76x on x86 platforms compared to FLT-based methods. Although we report numbers from a software implementation, we additionally provide a short glimpse of some recent results when these two algorithms are implemented on various hardware platforms. Finally, we also explore other exponentiation algorithms that work similarly to the Itoh-Tsuji inversion method. These algorithms perform fewer polynomial multiplications and show a better performance with 1.56x-1.96x on x86 platform compared to Itoh-Tsuji inversion method.
