Paper 2014/108

MJH: A Faster Alternative to MDC-2

Jooyoung Lee and Martijn Stam

Abstract

In this paper, we introduce a new class of double-block-length hash functions. Using the ideal cipher model, we prove that these hash functions, dubbed \MJH, are asymptotically collision resistant up to $O(2^{n(1-\epsilon)})$ query complexity for any $\epsilon>0$ in the iteration, where $n$ is the block size of the underlying blockcipher. When based on $n$-bit key blockciphers, our construction, being of rate 1/2, provides better provable security than MDC-2, the only known construction of a rate-1/2 double-length hash function based on an $n$-bit key blockcipher with non-trivial provable security. Moreover, since key scheduling is performed only once per message block for MJH, our proposal significantly outperforms MDC-2 in efficiency. When based on a $2n$-bit key blockcipher, we can use the extra $n$ bits of key to increase the amount of payload accordingly. Thus we get a rate-1 hash function that is much faster than existing proposals, such as Tandem-DM with comparable provable security. The proceedings version of this paper appeared in CT-RSA 2011.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Published elsewhere. DESIGNS, CODES AND CRYPTOGRAPHY
DOI
10.1007/s10623-014-9936-6
Keywords
hash functionblockcipherprovable securitycollision resistance
Contact author(s)
jlee05 @ sejong ac kr
History
2014-02-15: received
Short URL
https://ia.cr/2014/108
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2014/108,
      author = {Jooyoung Lee and Martijn Stam},
      title = {MJH: A Faster Alternative to MDC-2},
      howpublished = {Cryptology ePrint Archive, Paper 2014/108},
      year = {2014},
      doi = {10.1007/s10623-014-9936-6},
      note = {\url{https://eprint.iacr.org/2014/108}},
      url = {https://eprint.iacr.org/2014/108}
}
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