Bad directions in cryptographic hash functions

Daniel J.  Bernstein; Andreas Hülsing; Tanja Lange; Ruben Niederhagen

Paper 2015/151

Bad directions in cryptographic hash functions

Daniel J. Bernstein, Andreas Hülsing, Tanja Lange, and Ruben Niederhagen

Abstract

A 25-gigabyte "point obfuscation" challenge "using security parameter 60" was announced at the Crypto 2015 rump session; "point obfuscation" is another name for password hashing. This paper shows that the particular matrix-multiplication hash function used in the challenge is much less secure than previous password-hashing functions are believed to be. This paper's attack algorithm broke the challenge in just 19 minutes using a cluster of 21 PCs.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Preprint. MINOR revision.
Keywords: symmetric cryptography hash functions password hashing point obfuscation matrix multiplication meet-in-the-middle attacks meet-in-many-middles attacks
Contact author(s): authorcontact-obviouscation @ box cr yp to
History: 2015-02-27: received
Short URL: https://ia.cr/2015/151
License: CC BY

BibTeX

@misc{cryptoeprint:2015/151,
      author = {Daniel J.  Bernstein and Andreas Hülsing and Tanja Lange and Ruben Niederhagen},
      title = {Bad directions in cryptographic hash functions},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/151},
      year = {2015},
      url = {https://eprint.iacr.org/2015/151}
}