Preimages for Step-Reduced SHA-2

Jian Guo; Krystian Matusiewicz

Paper 2009/477

Preimages for Step-Reduced SHA-2

Jian Guo and Krystian Matusiewicz

Abstract

In this paper, we present a preimage attack for 42 step-reduced SHA-256 with time complexity $2^{251.7}$ and memory requirements of order $2^{12}$. The same attack also applies to 42 step-reduced SHA-512 with time complexity $2^{502.3}$ and memory requirements of order $2^{22}$. Our attack is meet-in-the-middle preimage attack.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Published elsewhere. A merged version will appear in ASIACRYPT2009
Keywords: preimage attack SHA-256 SHA-512 meet-in-the-middle hash function
Contact author(s): guojian @ ntu edu sg
History: 2009-10-01: revised; 2009-09-29: received; See all versions
Short URL: https://ia.cr/2009/477
License: CC BY

BibTeX

@misc{cryptoeprint:2009/477,
      author = {Jian Guo and Krystian Matusiewicz},
      title = {Preimages for Step-Reduced {SHA}-2},
      howpublished = {Cryptology {ePrint} Archive, Paper 2009/477},
      year = {2009},
      url = {https://eprint.iacr.org/2009/477}
}