講座名稱：Scalable Two-Round n-out-of-n and Multi-Signatures from Lattices in the Quantum Random Oracle Model

講座人：來齊齊 副教授

講座時間：6月14日16:00-18:00

地點(diǎn)：行政輔樓118-4

講座人介紹：

來齊齊，陜西師范大學(xué)計算機(jī)科學(xué)學(xué)院，副教授，碩士生導(dǎo)師。研究方向?yàn)楹罅孔影踩墓€密碼方案的設(shè)計與分析。2015年獲得西安電子科技大學(xué)密碼學(xué)專業(yè)博士學(xué)位。目前，在國際密碼學(xué)會頂級會議和期刊Eurocrypt，PKC，DCC等發(fā)表多篇論文。主持國家自然科學(xué)基金面上項目、青年項目各一項。獲黨政機(jī)要密碼科學(xué)技術(shù)獎三等獎一項。

講座內(nèi)容：

In this work, we construct the first efficient two-round n-out-of-n and multi-signatures from lattices in the quantum random oracle model (QROM), following the Fiat-Shamir with Aborts (FSwA) paradigm. Our protocols can be seen as the QROM variant of Damg?rd et.al.’s two round protocols (JoC 2022). Compared with other counterparts in the classical random oracle model, the notable feature of our protocol is that each party conducts independent abort, and outputs the signature with exactly two-round. Thus, our protocols are much more scalable.

The rewinding proof technique is the essential obstacle to achieving QROM security for the previously related work. In order to conquer it in an efficient way, we tweak and apply the online extractability by Unruh (Eurocrypt 2015). Besides, another significant technique contribution is demonstrating that a quantum-accessible pseudorandom function (QPRF) can be programmed and inverted simultaneously, even against a quantum adversary. Through using such a QPRF to simulate QROM, we can obtain protocols with much better efficiency.

主辦單位：數(shù)學(xué)與統(tǒng)計學(xué)院