**Speaker: **Dimitar Jetchev, EPFL - Inpher Inc.

**Title: **Rational Diophantine tuples and elliptic curves

**Date/Time:** December 2, 2019 / 12.40-13.30

**Place:** FENS G032

**Abstract:** Elliptic curves have received considerable attention from both mathematicians and computer scientists over the past 40 years. One of the main open questions in mathematics, the Birch and Swinnerton-Dyer conjecture, was formulated in the 60's as a result of extensive computer experiments in Cambridge University. I will go over the formulation of the conjecture and state some recent result on the formula for the leading term. We will then discuss questions from elliptic curve cryptography related to computation of isogenies and their applications to public-key cryptography. In the second part of the talk, I will discuss novel methods for high-precision privacy-preserving computing based on techniques from secure multiparty computation and Fourier approximations. We will finish by discussing some experimental results.

**BIO: ** Dr. Jetchev is the CTO and cofounder of Inpher, Inc leading research and development efforts. He is also a Professor of Mathematics at EPFL, Switzerland, funded by the Swiss National Science Foundation. He heads a research group in mathematical cryptology working on various fundamental problems in number theory and mathematical cryptology. Dimitar has developed algorithms for a prominent HFT firm in New York, and as a Microsoft Research Fellow at the Cryptography and Anti-Piracy Group he has contributed to the design and development of the Windows software-licensing scheme. Dr. Jetchev holds a B.A. in mathematics from Harvard University and M.A. and Ph.D. from University of California, Berkeley.

**Contact: **Michel Lavrauw