Bad Directions in Cryptographic Hash Functions

Conference paper

DOI: 10.1007/978-3-319-19962-7_28

Part of the Lecture Notes in Computer Science book series (LNCS, volume 9144)
Cite this paper as:
Bernstein D.J., Hülsing A., Lange T., Niederhagen R. (2015) Bad Directions in Cryptographic Hash Functions. In: Foo E., Stebila D. (eds) Information Security and Privacy. ACISP 2015. Lecture Notes in Computer Science, vol 9144. Springer, Cham


A 25-gigabyte “point obfuscation” challenge “using security parameter 60” was announced at the Crypto 2014 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.


Symmetric cryptography Hash functions Password hashing Point obfuscation Matrix multiplication Meet-in-the-middle attacks Meet-in-many-middles attacks 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Department of Computer ScienceUniversity of Illinois at ChicagoChicagoUSA
  2. 2.Department of Mathematics and Computer ScienceTechnische Universiteit EindhovenEindhovenThe Netherlands

Personalised recommendations