Security Enhancement of the Vortex Family of Hash Functions

Shay Gueron; Michael Kounavis

Paper 2011/652

Security Enhancement of the Vortex Family of Hash Functions

Shay Gueron and Michael Kounavis

Abstract

Vortex is a new family of one-way hash functions which has been submitted to the NIST SHA-3 competition. Its design is based on using the Rijndael block cipher round as a building block, and using a multiplication-based merging function to support fast mixing in a small number of steps. Vortex is designed to be a fast hash function, when running on a processor that has AES acceleration and has a proven collision resistance [2]. Several attacks on Vortex have been recently published [3, 4, 5, 6] exploiting some structural properties of its design, as presented in the version submitted to the SHA-3 competition. These are mainly ¯rst and second preimage attacks with time complexity below the ideal, as well as attempts to distinguish the Vortex output from random. In this paper we study the root-cause of the attacks and propose few amendments to the Vortex structure, which eliminate the attacks without a®ecting its collision resistance and performance.

Note: changed main author contact info

Metadata

Available format(s): PDF
Publication info: Preprint.
Contact author(s): michael_kounavis @ hotmail com
History: 2021-02-16: revised; 2011-12-09: received; See all versions
Short URL: https://ia.cr/2011/652
License: CC BY

BibTeX

@misc{cryptoeprint:2011/652,
      author = {Shay Gueron and Michael Kounavis},
      title = {Security Enhancement of the Vortex Family of Hash Functions},
      howpublished = {Cryptology {ePrint} Archive, Paper 2011/652},
      year = {2011},
      url = {https://eprint.iacr.org/2011/652}
}