From: 宋凌 <songling@iie.ac.cn>
Subject: [CRUNCHY CONTEST] 5 rounds, width 800, collision
Date: 11 July 2016 at 16:35:43 SGT
To: <crypto-competitions@googlegroups.com>
Cc: <crunchy@noekeon.org>, <guojian@ntu.edu.sg>, 乔珂欣 <qiaokexin@iie.ac.cn>, <meicheng.liu@gmail.com>

Dear Keccak Team and all,
We, Jian, Meicheng, Ling and Kexin, found solutions for collision challenge on Keccak[r=640, c=160, rounds=5], from round 0 to 4.

    counter += verifyCollisionChallenge(
        // Keccak[r=640, c=160, rounds=5]: collision challenge
        640, 160, 5,
        0, // fill in this line with the start round index (0=first)
        (const UINT8*)"\x3f\xb7\x7d\x29\x6d\xb4\x5f\xce\xab\xd5\xef\x63\xb2\xdb\x75\xab\xe7\x19\x01\x02\x73\x77\x92\x06\xa4\xa6\x45\xa6\xf8\xe3\xe6\x68\x62\x24\x28\x15\x83\xab\x3a\x63\xfb\xa5\xc7\x96\xb5\xbe\x4c\x5e\x96\x4c\x61\x92\xda\x47\x96\xdd\x4f\x09\xb0\xd4\x6f\x37\x68\x4c\x51\x37\xb6\xd3\x56\xab\x86\x62\x52\x7a\x57\xde\x0f\xea\x03\x90", 636, // bit length of message 1
        (const UINT8*)"\xcb\x0b\x15\x5b\xfc\xf2\xf3\xc0\xa5\xb5\x07\x59\xc3\x6d\x73\x22\xc5\xf0\x4c\x91\x63\x7d\x47\x87\x49\xa6\x75\xa6\x6f\xa9\xbe\x8b\xe3\x8a\xeb\x52\x41\x2d\x40\x19\xc3\x4c\xfb\xd9\x30\xd6\x9f\x66\x71\xfc\xc9\xd8\x54\x85\x55\x57\x4a\xf6\x62\x06\xc5\xb5\xb4\x64\x56\xbf\x12\x7f\xf0\xdb\xea\x2b\x10\x7b\x20\xf6\x87\x97\xfd\xf2", 638 // bit length of message 2
     );
The 160-bit digest is:

ba 5a 0b f9 2d 68 30 74 62 8c 66 85 ad b0 e1 66 35 ac 52 b0


Best Regards,

Kexin Qiao (2,3,1,4) and Ling Song (1,2,3) and Meicheng Liu (1,2) and Jian Guo (1)

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