• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.5
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• pp.57-68
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• 2004

The rectangle attack and the related-key attack on block ciphers are well-known to be very powerful. In this paper we combine the rectangle attack with the related-key attack. Using this combined attack we can attack the SHACAL-1 cipher with 512-bit keys up to 59 out of its 80 rounds. Our 59-round attack requires a data complexity of $2^{149.72}$ chosen plaintexts and a time complexity of $2^{498.30}$ encryptions, which is faster than exhaustive search.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.3
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• pp.115-126
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• 2005

SHACAL-2 is a 256-bit block cipher with up to 512 bits of key length based on the hash function SHA-2. It was submitted to the the NESSIE project and was recommended as one of the NESSIE selections. In this paper, we present two types of related-key attacks called the related-key differential-(non)linear and the related-key rectangle attacks, and we discuss the security of SHACAL-2 against these two types of attacks. Using the related-key differential-nonlinear attack, we can break SHACAL-2 with 512-bit keys up to 35 out of its 64 rounds, and using the related-key rectangle attack, we can break SHACAL-2 with 512-bit keys up to 37 rounds.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.39-48
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• 2009

In this paper we improve previous related-key rectangle attacks on AES from 9 rounds to 10 rounds: Our attacks break the first 10 rounds of 12-round AES-192 with 256 related keys, a data complexity of $2^{124}$ and a time complexity of $2^{183}$, and also break the first 10 rounds of 12-round AES-192 with 64 related keys, a data complexity of $2^{122}$ and a time complexity of $2^{183.6}$, Our attacks are the best knoown attacks on AES-192.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.644-652
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• 2009

New communication environments such as USN, WiBro and RFID have been realized nowadays. Thus, in order to ensure security and privacy protection, various light-weight block ciphers, e.g., mCrypton, HIGHT, SEA and PRESENT, have been proposed. The block cipher mCrypton, which is a light-weight version of Crypton, is a 64-bit block cipher with three key size options (64 bits, 96 bits, 128 bits). In this paper we show that 8-round mCrypton with 128-bit key is vulnerable to related-key rectangle attack. It is the first known cryptanalytic result on mCrypton. We first describe how to construct two related-key truncated differentials on which 7-round related-key rectangle distinguisher is based and then exploit it to attack 8-round mCrypton. This attack requires $2^{45.5}$dada and $2^{45.5}$time complexities which is faster than exhaustive key search.

• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.69-75
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• 2011

In this paper, we analyze the key schedule of the block cipher SEED-192. According to the result of this paper, there exist weak keys in 16 out of 20 rounds of SEED-192 against the related-key rectangle/boomerang attack. This is the first cryptanalytic result for the key schedule of SEED-192.