Related-Key Impossible Diferential Attack on Reduced-Round LBlock

• 作 者: 温隆 王美琴 赵静远
• 机 构: Key Laboratory of Cryptologic Technology and Information Security, Ministry of Education, Shandong U
• 出 处: Journal of Computer Science & Technology
• 发表日期: 2014年01期
• 关键词: impossible Round lightweight cipher satisfying Number Complexity guess schedule

LBlock is a 32-round lightweight block cipher with 64-bit block size and 80-bit key. This paper identifies 16-round related-key impossible diferentials of LBlock, which are better than the 15-round related-key impossible diferentials used in the previous attack. Based on these 16-round related-key impossible diferentials, we can attack 23 rounds of LBlock while the previous related-key impossible diferential attacks could only work on 22-round LBlock. This makes our attack on LBlock the best attack in terms of the number of attacked rounds.

This paper identifies 16-round related-key impossible diferentials of LBlock, which are better than the 15-round related-key impossible diferentials used in the previous attack. Based on these 16-round related-key impossible diferentials, we can attack 23 rounds of LBlock while the previous related-key impossible diferential attacks could only work on 22-round LBlock. This makes our attack on LBlock the best attack in terms of the number of attacked rounds.