Paper 2014/223
Collision Spectrum, Entropy Loss, T-Sponges, and Cryptanalysis of GLUON-64
Léo Perrin and Dmitry Khovratovich
Abstract
In this paper, we investigate the properties of iterative non-injective functions and the security of primitives where they are used. First, we introduce the Collision Probability Spectrum (CPS) parameter to quantify how far from a permutation a function is. In particular, we show that the output size decreases linearly with the number of iterations whereas the collision trees grow quadratically. Secondly, we investigate the T-sponge construction and show how certain CPS and rate values lead to an improved preimage attack on long messages. As an example, we find collisions for the GLUON-64 internal function, approximate its CPS, and show an attack that violates the security claims. For instance, if a message ends with a sequence of 1~Mb (respectively 1~Gb) of zeros, then our preimage search takes time $2^{115.3}$ (respectively $2^{105.3}$) instead of $2^{128}$.
Metadata
- Available format(s)
-
PDF
- Category
- Secret-key cryptography
- Publication info
- Published by the IACR in FSE 2014
- Keywords
- random functionCollision Probability Spectrumcollision treeT-spongeGLUONcollision search
- Contact author(s)
- leo perrin @ uni lu
- History
- 2014-03-28: received
- Short URL
- https://ia.cr/2014/223
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2014/223,
author = {Léo Perrin and Dmitry Khovratovich},
title = {Collision Spectrum, Entropy Loss, T-Sponges, and Cryptanalysis of {GLUON}-64},
howpublished = {Cryptology {ePrint} Archive, Paper 2014/223},
year = {2014},
url = {https://eprint.iacr.org/2014/223}
}
