Table of contents

  • This session has been presented March 06, 2026 (13:45 - 14:45).

Description

  • Speaker

    Radu Toma - Sorbonne Université

In joint work with Koen de Boer, Aurel Page, and Benjamin Wesolowski, we study the hardness of the approximate Shortest Independent Vectors Problem (SIVP) for random module lattices. We use here a natural notion of randomness as defined originally by Siegel through Haar measures. By proving a reduction, we show it is essentially as hard as the problem for arbitrary instances. While this was previously known for ideal lattices (those of rank 1), it is the first such result in higher rank. I will give an overview of the reduction and discuss some of the challenges. The work involves deep number theoretic techniques and results, such as the equidistribution of Hecke points, which we study using the spectral theory of automorphic forms. This talk should be accessible to both cryptographers as well as number theorists.

Next sessions

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    • April 10, 2026 (13:45 - 14:45)

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    Speaker : Min-Yi Shen - No Affiliation

    One of the fundamental hardness assumptions underlying isogeny-based cryptography is the problem of finding a non-trivial endomorphism of a given supersingular elliptic curve. In this talk, we show that the problem is related to the problem of finding a splitting of a principally polarised superspecial abelian surface. In particular, we provide formal security reductions and a proof-of-concept[…]
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