New Preimage Attack on MDC-4

Deukjo Hong; Daesung Kwon

Paper 2012/633

New Preimage Attack on MDC-4

Deukjo Hong and Daesung Kwon

Abstract

In this paper, we provide some cryptanalytic results for double-block-length (DBL) hash modes of block ciphers, MDC-4. Our preimage attacks follow the framework of Knudsen et al.'s time/memory trade-off preimage attack on MDC-2. We find how to apply it to our objects. When the block length of the underlying block cipher is $n$ bits, the most efficient preimage attack on MDC-4 requires time and space about $2^{3n/2}$, which is to be compared to the previous best known preimage attack having time complexity of $2^{7n/4}$. Additionally, we propose an enhanced version of MDC-4, MDC-4$^*$ based on a simple idea. It is secure against our preimage attack and previous attacks and has the same efficiency as MDC-4.

Note: A typo in reference is corrected.

Metadata

Available format(s): PDF
Publication info: Published elsewhere. Unknown where it was published
Keywords: MDC-4 Hash Function Preimage
Contact author(s): hongdj @ ensec re kr
History: 2012-11-13: revised; 2012-11-11: received; See all versions
Short URL: https://ia.cr/2012/633
License: CC BY

BibTeX

@misc{cryptoeprint:2012/633,
      author = {Deukjo Hong and Daesung Kwon},
      title = {New Preimage Attack on {MDC}-4},
      howpublished = {Cryptology {ePrint} Archive, Paper 2012/633},
      year = {2012},
      url = {https://eprint.iacr.org/2012/633}
}