-------------------------------------------------------------------------- From: Stefan Kölbl Subject: [CRUNCHY CONTEST] 4 rounds, width 400/800, collision Date: Mon, June 17, 2013 16:39 To: crunchy at noekeon.org -------------------------------------------------------------------------- Dear Keccak team, On behalf of our group (Stefan Kölbl, Florian Mendel, Martin Schläffer and Tomislav Nad), I would like to share with you our solutions on the Keccak challenges Keccak[r = 240, c = 160, nr = 4] and Keccak[r = 640, c = 160, nr = 4], which are closed. As no solution has been published for a while, you might still be interested with these results. By using the 4-round attack scenario proposed by Dinur et al., we were able to obtain these results by combining new high probability paths with an automatic search tool [1]. The solutions are attached in the format of the Keccak Tools so you can verify them easily. Best regards, Stefan --- keccak_challenges.txt --- counter += verifyCollisionChallenge( // Keccak[r=240, c=160, rounds=4]: collision challenge 240, 160, 4, (const UINT8*)"\xFD\xA3\x35\x10\x12\xB2\x7E\xBC\xE6\x14\xEA\xFA\x6A\xB6\xF8\x6F\xB0\x51\xE6\x1F\x76\x3C\x69\xE9\x20\x45\xE9\xC1\x60\xD5", 238, (const UINT8*)"\xBC\x45\x5E\x60\x53\xBE\x8E\x1F\x64\x35\xB5\x2B\x37\x42\x0E\x3E\x45\xA0\x3F\x3C\x68\xE2\xDA\xE2\x6E\x72\xAA\xED\x20\xDA", 238 ); counter += verifyCollisionChallenge( // Keccak[r=640, c=160, rounds=4]: collision challenge 640, 160, 4, (const UINT8*)"\x92\x81\x80\x4A\x71\x78\xB0\xC6\xF4\x3C\xE4\x72\x5D\xA5\xD8\x38\x5B\xB3\x80\x59\x24\x4D\x70\x41\xF4\xB7\xAE\x63\xFA\x6D\xDE\x07\x29\x58\x23\x5A\x59\x29\xCF\x29\x23\xA6\x2C\xAA\x89\xF4\xBD\xA1\xBC\x2C\xBA\xE7\x91\x43\x30\xE2\x19\x7F\xEF\x4F\x3C\xB5\xFF\x5E\xCF\x2F\x9B\x8D\x1C\x85\x3A\x71\x41\xD9\x27\x17\x50\xC0\xA8\xCA", 638, (const UINT8*)"\x5C\x8C\x47\x64\xF2\xBB\x20\x8A\x28\xC1\x1F\xC6\xA5\x09\x3E\xF3\x67\x5A\x08\x90\x6B\x0D\x19\xDE\x1A\x2A\xE6\x67\x30\x02\x52\x05\x21\x5C\x6F\x32\xF5\xF9\x3E\x16\x40\x4B\x41\xDC\x6B\x78\xDE\x61\xF4\xA3\x32\x66\x13\xE7\x1D\xB7\xD0\xD8\x2F\x84\xA6\x80\xA6\xCD\x35\xB6\x00\xD8\x0A\x91\xE0\x44\x6B\xB6\x55\x07\x78\x88\x28\xDB", 638 ); --- [1] http://link.springer.com/chapter/10.1007%2F978-3-642-25385-0_16