TY - GEN
T1 - Tweakable enciphering schemes from hash-sum-expansion
AU - Minematsu, Kazuhiko
AU - Matsushima, Toshiyasu
PY - 2007/12/1
Y1 - 2007/12/1
N2 - We study a tweakable blockcipher for arbitrarily long message (also called a tweakable enciphering scheme) that consists of a universal hash function and an expansion, a keyed function with short input and long output. Such schemes, called HCTR and HCH, have been recently proposed. They used (a variant of) the counter mode of a blockcipher for the expansion. We provide a security proof of a structure that underlies HCTR and HCH. We prove that the expansion can be instantiated with any function secure against Known-plaintext attacks (KPAs), which is called a weak pseudorandom function (WPRF). As an application of our proof, we provide efficient blockcipher-based schemes comparable to HCH and HCTR. For the double-block-length case, our result is an interesting extension of previous attempts to build a doubleblock-length cryptographic permutation using WPRF.
AB - We study a tweakable blockcipher for arbitrarily long message (also called a tweakable enciphering scheme) that consists of a universal hash function and an expansion, a keyed function with short input and long output. Such schemes, called HCTR and HCH, have been recently proposed. They used (a variant of) the counter mode of a blockcipher for the expansion. We provide a security proof of a structure that underlies HCTR and HCH. We prove that the expansion can be instantiated with any function secure against Known-plaintext attacks (KPAs), which is called a weak pseudorandom function (WPRF). As an application of our proof, we provide efficient blockcipher-based schemes comparable to HCH and HCTR. For the double-block-length case, our result is an interesting extension of previous attempts to build a doubleblock-length cryptographic permutation using WPRF.
KW - HCH
KW - HCTR
KW - Mode of operation
KW - Weak pseudorandom function
UR - http://www.scopus.com/inward/record.url?scp=38349022443&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38349022443&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:38349022443
SN - 9783540770251
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 252
EP - 267
BT - Progress in Cryptology - INDOCRYPT 2007 - 8th International Conference on Cryptology in India, Proceedings
T2 - 8th Annual International Conference on Cryptolology in India, INDOCRYPT 2007
Y2 - 9 December 2007 through 13 December 2007
ER -