A Combinatorial Analysis of HC-128

Goutam Paul; Subhamoy Maitra; Shashwat Raizada

Paper 2010/387 Original: eprint.iacr.org/2010/387 ↗

A Combinatorial Analysis of HC-128

Goutam Paul

Subhamoy Maitra

Shashwat Raizada

Abstract

We show that the knowledge of any one of the two internal state arrays of HC-128 along with the knowledge of 2048 keystream words is sufficient to construct the other state array completely in $2^{42}$ time complexity. Though our analysis does not lead to any attack on HC-128, it reveals a structural insight into the cipher. In the process, we theoretically establish certain combinatorial properties of HC-128 keystream generation algorithm. We also suggest a modification to HC-128 that takes care of the recently known cryptanalytic results with little reduction in speed.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Preprint.
History: 2011-11-16: last updated; 2010-07-09: published
Short URL: https://ia.cr/2010/387
License: https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2010/387,
      author = {Goutam Paul and Subhamoy Maitra and Shashwat Raizada},
      title = {A Combinatorial Analysis of HC-128},
      howpublished = {Cryptology {ePrint} Archive, Paper 2010/387},
      year = {2010},
      url = {https://eprint.iacr.org/2010/387}
}