报告人：王浩洋

腾讯会议：846-883-859

报告时间：2024-09-25 19:30

报告题目：Impossible Boomerang Attacks Revisited

报告摘要：

The impossible boomerang (IB) attack was first introduced by Lu in his doctoral thesis and subsequently published at DCC in 2011. The IB attack is a variant of the impossible differential (ID) attack by incorporating the idea of the boomerang attack. In this paper, we revisit the IB attack, and introduce the incompatibility of two characteristics in boomerang to the construction of an IB distinguisher. With our methodology, all the constructions of IB distinguisher are represented in a unified manner. Moreover, we show that the related-(twea)key IB distinguishers possess more freedom than the ones of ID so that it can cover more rounds.

We also propose a new tool based on Mixed-Integer Quadratically-Constrained Programming (MIQCP) to search for IB attacks. To illustrate the power of the IB attack, we mount attacks against three tweakable block ciphers: Deoxys-BC, Joltik-BC and SKINNY. For Deoxys-BC, we propose a related-tweakey IB attack on 14-round Deoxys-BC-384, which improves the best previous related-tweakey ID attack by 2 rounds, and we improve the data complexity of the best previous related-tweakey ID attack on 10-round Deoxys-BC-256. For Joltik-BC, we propose the best attacks against 10-round Joltik-BC-128 and 14-round Joltik-BC-192 with related-tweakey B attack. For SKINNY-n-3n, we propose a 27-round related-tweakey IB attack, which improves both the time and the memory complexities of the best previous ID attack. We also propose the first related-tweakey IB attack on 28-round SKINNY-n-3n, which improves the previous best ID attack by one round.

报告人简介：

王浩洋，2016年于벳 365 코리아获得学士学位，2021年于新加坡南洋理工大学获得博士学位，2021年加入上海交通大学벳 365 코리아，现任助理教授。

研究方向为对称密码学。在CRYPTO、FSE等国际主流会议发表多篇文章，并获得2022年ACISP会议最佳论文奖。获得新加坡数学协会颁发的优秀博士论文奖章。

邀请人：胡凯

审核人：魏普文