TY - GEN
T1 - A related-key rectangle attack on the full KASUMI
AU - Biham, Eli
AU - Dunkelman, Orr
AU - Keller, Nathan
PY - 2005
Y1 - 2005
N2 - KASUMI is an 8-round Feistel block cipher used in the confidentiality and the integrity algorithms of the 3GPP mobile communications. As more and more 3GPP networks are being deployed, more and more users use KASUMI to protect their privacy. Previously known attacks on KASUMI can break up to 6 out of the 8 rounds faster than exhaustive key search, and no attacks on the full KASUMI have been published. In this paper we apply the recently introduced related-key boomerang and rectangle attacks to KASUMI, resulting in an attack that is faster than exhaustive search against the full cipher. We also present a related-key boomerang distinguisher for 6-round KASUMI using only 768 adaptively chosen plaintexts and ciphertexts encrypted or decrypted under four related keys. Recently, it was shown that the security of the entire encryption system of the 3GPP networks cannot be proven using only the "ordinary" assumption that the underlying cipher (KASUMI) is a Pseudo-Random Permutation. It was also shown that if we assume that KASUMI is also secure with respect to differential-based related-key attacks then the security of the entire system can be proven. Our results show that theoretically, KASUMI is not secure with respect to differential-based related-key attacks, and thus, the security of the entire encryption system of the 3GPP cannot be proven at this time.
AB - KASUMI is an 8-round Feistel block cipher used in the confidentiality and the integrity algorithms of the 3GPP mobile communications. As more and more 3GPP networks are being deployed, more and more users use KASUMI to protect their privacy. Previously known attacks on KASUMI can break up to 6 out of the 8 rounds faster than exhaustive key search, and no attacks on the full KASUMI have been published. In this paper we apply the recently introduced related-key boomerang and rectangle attacks to KASUMI, resulting in an attack that is faster than exhaustive search against the full cipher. We also present a related-key boomerang distinguisher for 6-round KASUMI using only 768 adaptively chosen plaintexts and ciphertexts encrypted or decrypted under four related keys. Recently, it was shown that the security of the entire encryption system of the 3GPP networks cannot be proven using only the "ordinary" assumption that the underlying cipher (KASUMI) is a Pseudo-Random Permutation. It was also shown that if we assume that KASUMI is also secure with respect to differential-based related-key attacks then the security of the entire system can be proven. Our results show that theoretically, KASUMI is not secure with respect to differential-based related-key attacks, and thus, the security of the entire encryption system of the 3GPP cannot be proven at this time.
UR - http://www.scopus.com/inward/record.url?scp=33646781279&partnerID=8YFLogxK
U2 - 10.1007/11593447_24
DO - 10.1007/11593447_24
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AN - SCOPUS:33646781279
SN - 3540306846
SN - 9783540306849
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 442
EP - 461
BT - Advances in Cryptology - ASIACRYPT 2005 - 11th International Conference on the Theory and Application of Cryptology and Information Security, Proceedings
PB - Springer Verlag
T2 - 11th International Conference on the Theory and Application of Cryptology and Information Security, ASIACRYPT 2005
Y2 - 4 December 2005 through 8 December 2005
ER -