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Subject: 	[CRUNCHY CONTEST] 6 rounds, width 1600, collision
Date: 	26/02/17 06:29
From: 	宋凌 <songling at iie ac cn>
To:     crypto-competitions at googlegroups com
Cc:     guojian at ntu edu sg, liaogh cs at gmail com, songling at ntu edu sg
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Dear Keccak Team and all,

We, Ling, Guohong, and Jian, found a solution for collision challenge on Keccak[r=1440, c=160, rounds=6], from round 0 to 5. The techniques used here are non-trivial extensions of those used for finding 5-round solutions. The computation of this solution took around 2^50 4.5-round Keccak evaluations. More details will be disclosed soon.


    counter += verifyCollisionChallenge(
        // Keccak[r=1440, c=160, rounds=6]: collision challenge
        1440, 160, 6,
        0, // fill in this line with the start round index (0=first)
(const UINT8*)"\x9d\x35\xec\xb7\xe5\xab\x27\xda\x6a\x25\x0e\xcd\xb4\x2a\x8a\x32\x0e\x39\x84\xa1\xec\xde\xdb\x00\xf4\x45\xc7\x81\x64\xf6\x43\x38\x94\xf5\xd4\x39\xef\x3b\xf8\xdd\x7a\xc9\x72\x02\x96\x2a\xba\x46\x58\x55\x18\x13\x3e\xce\xc8\x8c\x32\x65\x54\x62\xc6\x6c\x7c\x2d\xb8\xf4\xc7\x5d\xc2\xcd\x8d\x4d\x94\xbf\x85\x3f\xf4\x52\x42\x57\xee\xbd\x4c\xb0\xd6\xa2\xcf\xbd\x96\x75\x8a\x16\x02\x7a\x8d\x20\x92\x87\xa6\xf0\x52\xc6\xe7\xaf\x6f\x91\x85\x8d\x74\x04\x7c\x46\xc3\x97\x4b\x3c\xf6\xea\xbf\xf1\xd4\x7c\x88\x35\xea\xaa\xb0\xc2\x4d\x43\x84\x9d\x3f\xd2\xa3\x72\x61\x0b\x59\x90\xa0\xd9\xa5\x97\x7e\x32\xd4\xdb\x62\xec\xe1\xbb\xc5\x62\xe4\x9b\xcb\x4b\x28\x64\x6a\x10\x5e\xb5\xc8\xcb\x43\x88\x00\x81\xc4\x1a\x6a\xd9\x3d\xdd\x67\x1d\x15\xe9\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 1438, // Message 1
(const UINT8*)"\x10\x89\x27\x30\x07\x64\x0c\x5a\x0b\x0c\x79\x24\xd7\xa7\xc1\x32\x3a\xa8\x04\x64\xc4\x75\xce\x8b\x31\x7e\xce\x2e\xe9\x23\xce\x7f\x85\xc7\x32\xf9\xf9\x08\xee\x1b\xf9\x17\x6b\xeb\x55\xba\x69\x39\xa8\xc6\x21\x6c\xb0\x48\x29\xe8\x1f\x2c\x20\x22\xef\xac\x42\xaf\x60\xfb\x96\xbf\x90\xbd\xc1\xa9\xda\x7b\xb5\x36\x7c\xe2\x98\x0f\x0f\xc7\x88\x3d\x45\x26\x2b\xa0\xe6\xc7\x19\xc9\x4d\xf7\xc5\x5e\xdd\xc8\xa3\x23\x7a\x1d\x39\x31\x75\xf2\xc7\x0a\xad\xcd\xbe\xc0\x90\xd3\xc9\xb2\xf6\x28\xfa\x14\x17\x82\x25\xef\xea\x7e\xf6\x69\x78\x71\xd3\xce\xed\x7f\x9b\x15\x7d\xca\x1c\x29\xb0\xc2\x89\xda\xae\x14\x94\x98\x9f\xe7\xdd\x7b\x4b\x5b\xe1\x92\xe1\xcb\x88\x30\xa9\xce\x48\x5c\x86\x17\x86\x13\x74\x13\xad\xe3\xe5\x7c\x91\x2a\x60\x5e\x42\x98\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 1436 // Message 2
     );


The 160-bit digest is:
89 90 10 97 dd 33 21 60 05 0f 4b 91 25 51 1b 61 c0 96 2b 53

Best Regards,

Ling Song (1,2,3) and Guohong Liao (4,1) 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. South China Normal University, China