Key recovery attacks on reduced-round Joltik-BC in the single-key setting

摘要

Joltik-BC is a tweakable block cipher used in the CAESAR candidate Joltik. In this paper, we propose meet-in-the-middle attacks on Joltik-BC in the single-key setting. Our attacks are constructed utilizing the freedom of the tweak and differential enumeration technique. As a result, we get an attack on 8-round Joltik-BC-64-64 with a data complexity of 2(53.5), a memory complexity of 2(53) and a time complexity of 2(53.6). We also present an attack on 10-round Joltik-BC-128-64 with a data complexity of 2(56.1) , a memory complexity of 2(123.5) and a time complexity of 2(126.5). As far as we know, these are the best single-key attacks on Joltik-BC. (C) 2019 Elsevier B.V. All rights reserved.