We congratulate Jian Guo¹, Meicheng Liu^1,2, Ling Song^1,2,3 and Kexin Qiao^2,3,1,4 for solving another 5-round collision challenge in the Keccak Crunchy Crypto Collision and Pre-image Contest!

They generated a collision for a Keccak variant with capacity 160 bits, calling the Keccak-f permutation with width 800 and 5 rounds.

This solution happens less than two months after their team published the solution for the 5-round collision challenge with width 1600. We are looking forward to seeing the details of this attack, how much it differs from their previous one and whether their method can be adapted for the two remaining collision challenges in the 5-round category.

1. Cryptanalysis Taskforce, Temasek Laboratories @ Nanyang Technological University, Singapore
2. State Key Laboratory of Information Security, Institute of Information Engineering, Chinese Academy of Sciences, China
3. Data Assurance and Communication Security Research Center, Chinese Academy of Sciences, China
4. University of Chinese Academy of Sciences, China