TY - JOUR
T1 - Weak-key classes of 7-round MISTY 1 and 2 for related-key amplified boomerang attacks
AU - Lee, Eunjin
AU - Kim, Jongsung
AU - Hong, Deukjo
AU - Lee, Changhoon
AU - Sung, Jaechul
AU - Hong, Seokhie
AU - Lim, Jongin
PY - 2008
Y1 - 2008
N2 - In 1997, M. Matsui proposed secret-key cryptosystems called MISTY 1 and MISTY 2, which are 8-and 12-round block ciphers with a 64-bit block, and a 128-bit key. They are designed based on the principle of provable security against differential and linear cryptanalysis. In this paper we present large collections of weak-key classes encompassing 273 and 270 weak keys for 7-round MISTY 1 and 2 for which they are vulnerable to a related-key amplified boomerang attack. Under our weak-key assumptions, the related-key amplified boomerang attack can be applied to 7-round MISTY 1 and 2 with 254, 256 chosen plaintexts and 255.3 7-round MISTY 1 encryptions, 265 7-round MISTY 2 encryptions, respectively.
AB - In 1997, M. Matsui proposed secret-key cryptosystems called MISTY 1 and MISTY 2, which are 8-and 12-round block ciphers with a 64-bit block, and a 128-bit key. They are designed based on the principle of provable security against differential and linear cryptanalysis. In this paper we present large collections of weak-key classes encompassing 273 and 270 weak keys for 7-round MISTY 1 and 2 for which they are vulnerable to a related-key amplified boomerang attack. Under our weak-key assumptions, the related-key amplified boomerang attack can be applied to 7-round MISTY 1 and 2 with 254, 256 chosen plaintexts and 255.3 7-round MISTY 1 encryptions, 265 7-round MISTY 2 encryptions, respectively.
KW - Block ciphers
KW - MISTY 1
KW - MISTY 2
KW - Related-key amplified boomerang attack
KW - Weak-key classes
UR - http://www.scopus.com/inward/record.url?scp=67049120785&partnerID=8YFLogxK
U2 - 10.1093/ietfec/e91-a.2.642
DO - 10.1093/ietfec/e91-a.2.642
M3 - Article
AN - SCOPUS:67049120785
SN - 0916-8508
VL - E91-A
SP - 642
EP - 649
JO - IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
JF - IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
IS - 2
ER -