Speaker: Yan Jiayun, PhD student, East China Normal University

Date: December 10, 2025

Time: 16:30-18:00 pm

Location: B1032, Zhixin Building, Shandong University

Sponsor: School of Mathematics, Shandong University

Abstract:

We present fully adaptive secure threshold IBE and threshold signatures, which rely on the k-Linear assumption in the standard model over asymmetric pairing groups. In particular, our threshold signature scheme achieves a non-interactive signing process and an adaptively secure guarantee as strong as Das-Ren (CRYPTO'24), while their proof relies on the random oracle model. We achieve our results by following steps: First, we design two threshold IBE schemes against adaptive corruptions in the composite-order and prime-order groups by adopting the dual system groups encoding. Second, we provide a generic transform from threshold IBE to threshold signatures, following Naor's paradigm, which reduces the fully adaptive corruption security of threshold signatures to threshold IBE. Third, we present two threshold signatures instantiations in composite-order and prime-order groups.

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https://www.view.sdu.edu.cn/info/1020/208576.htm