Functional Graph Revisited: Updates on (Second) Preimage Attacks on Hash Combiners

Zhenzhen Bao; Lei Wang; Jian Guo; Dawu Gu

Paper 2017/534

Functional Graph Revisited: Updates on (Second) Preimage Attacks on Hash Combiners

Zhenzhen Bao, Lei Wang, Jian Guo, and Dawu Gu

Abstract

This paper studies functional-graph-based (second) preimage attacks against hash combiners. By exploiting more properties of cyclic nodes of functional graph, we find an improved preimage attack against the XOR combiner with a complexity of $2^{5n/8}$, while the previous best-known complexity is $2^{2n/3}$. Moreover, we find the first generic second-preimage attack on Zipper hash with an optimal complexity of $2^{3n/5}$.

Note: Full version, revise the content regarding the expected number of trials reaching deep-iterates simultaneously

Metadata

Available format(s): PDF
Publication info: A minor revision of an IACR publication in CRYPTO 2017
Keywords: Hash Combiner Functional Graph XOR Combiner Zipper Hash (Second) Preimage Attack
Contact author(s): wanglei_hb @ sjtu edu cn
History: 2017-08-19: revised; 2017-06-07: received; See all versions
Short URL: https://ia.cr/2017/534
License: CC BY

BibTeX

@misc{cryptoeprint:2017/534,
      author = {Zhenzhen Bao and Lei Wang and Jian Guo and Dawu Gu},
      title = {Functional Graph Revisited: Updates on (Second) Preimage Attacks on Hash Combiners},
      howpublished = {Cryptology {ePrint} Archive, Paper 2017/534},
      year = {2017},
      url = {https://eprint.iacr.org/2017/534}
}