eprint.iacr.org will be offline for approximately an hour for routine maintenance again at 10pm UTC on Wednesday, April 17.

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 cryptographyhash functionspassword hashingpoint obfuscationmatrix multiplicationmeet-in-the-middle attacksmeet-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
Creative Commons Attribution
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},
      note = {\url{https://eprint.iacr.org/2015/151}},
      url = {https://eprint.iacr.org/2015/151}
}
Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.