A Chosen IV Related Key Attack on Grain-128a

Published

July 24, 2013

Author(s)

Subhadeep Banik, Subhamoy Maitra, Santanu (. Sarkar, Meltem Sonmez Turan

Abstract

Due to the symmetric padding used in the stream cipher Grain v1 and Grain-128, it is possible to find Key-IV pairs that generate shifted keystreams efficiently. Based on this observation, Lee et al. presented a related-Key chosen IV attack on Grain v1 and Grain-128 in ACISP 2008. Later, the designers introduced Grain-128a having an asymmetric padding. As a result, the existing idea of related-Key chosen IV attack does not work on this new design. In this paper, we present a key recovery attack on Grain-128a, in a related-Key chosen IV setting. We show that using around $\gamma \cdot 2^32}$ ($\gamma$ is a constant related to actual experimentation and it is sufficient to estimate it as $2^8$) related keys and $\gamma \cdot 2^64}$ chosen IVs, it is possible to obtain $32\cdot \gamma$ simple nonlinear equations and solve them to recover the secret key in Grain-128a.

Proceedings Title

Proceedings of 18th Australasian Conference on Information Security and Privacy

Volume

7959

Conference Dates

July 1-3, 2013

Conference Location

Brisbane, AU

Conference Title

18th Australasian Conference on Information Security and Privacy

Pub Type

Conferences

Download Paper

https://doi.org/10.1007/978-3-642-39059-3_2

Local Download

Keywords

Cryptanalysis, eStream, Grain-128a, Related Keys, Stream Cipher

Citation

Banik, S. , Maitra, S. , Sarkar, S. and Sonmez Turan, M. (2013), A Chosen IV Related Key Attack on Grain-128a, Proceedings of 18th Australasian Conference on Information Security and Privacy, Brisbane, AU, [online], https://doi.org/10.1007/978-3-642-39059-3_2, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=913678 (Accessed October 15, 2025)