Paper 2012/696

Cryptanalysis of RAKAPOSHI Stream Cipher

Lin Ding and Jie Guan

Abstract

RAKAPOSHI is a hardware oriented stream cipher designed by Carlos Cid et al. in 2009. The stream cipher is based on Dynamic Linear Feedback Shift Registers, with a simple and potentially scalable design, and is particularly suitable for hardware applications with restricted resources. The RAKAPOSHI stream cipher offers 128-bit security. In this paper, we point out some weaknesses in the cipher. Firstly, it shows that there are 2^192 weak (key, IV) pairs in RAKAPOSHI stream cipher. Secondly, for weak (key, IV) pairs of RAKAPOSHI, they are vulnerable to linear distinguishing attack and algebraic attack. Finally, we propose a real time related key chosen IV attack on RAKAPOSHI. The attack on RAKAPOSHI recovers the 128-bit secret key of with a computational complexity of 2^37, requiring 47 related keys, 2^8 chosen IVs and 2^14.555 keystream bits. The success probability of this attack is 0.999, which is quite close to 1. The experimental results corroborate our assertion.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Published elsewhere. The paper had been submitted and is under review now.
Keywords
Cryptanalysislinear distinguishing attackalgebraic attackrelated key chosen IV attackRAKAPOSHIstream cipher.
Contact author(s)
dinglin_cipher @ 163 com
History
2012-12-14: received
Short URL
https://ia.cr/2012/696
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2012/696,
      author = {Lin Ding and Jie Guan},
      title = {Cryptanalysis of RAKAPOSHI Stream Cipher},
      howpublished = {Cryptology ePrint Archive, Paper 2012/696},
      year = {2012},
      note = {\url{https://eprint.iacr.org/2012/696}},
      url = {https://eprint.iacr.org/2012/696}
}
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