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

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

讲座人：来齐齐 副教授

讲座时间：6月14日16:00-18:00

地点：行政辅楼118-4

讲座人介绍：

来齐齐，陕西师范大学计算机科学学院，副教授，硕士生导师。研究方向为后量子安全的公钥密码方案的设计与分析。2015年获得奥门金沙集团3354CC密码学专业博士学位。目前，在国际密码学会顶级会议和期刊Eurocrypt，PKC，DCC等发表多篇论文。主持国家自然科学基金面上项目、青年项目各一项。获党政机要密码科学技术奖三等奖一项。

讲座内容：

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 Damgård 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.

主办单位：数学与统计学院