article · 2025
Conditional Differential Attack on Lightweight Stream Cipher Atom
Xiaojuan Lu, Zixin Tan, Hongcai Xin
Cited by 0Abstract and details only
Abstract
Knellwolf et al. introduced a conditional differential attack on NFSR-based cryptosystems at ASIACRYPT 2010. Since then, this method has been extensively employed to evaluate the security of various cryptographic algorithms with Grain family structures. Atom is a small-state stream cipher with a 159-bit internal state, based on the Grain family structure, and offers 128-bit security. It was proposed by Subhadeep Banik et al. in ToSC 2021. Given its structure and security claims, Atom presents an interesting target for further cryptanalysis. In this paper, we conduct a detailed study of conditional differential attacks on Atom. We first investigate the difference propagation of roundreduced Atom with differential algebraic transitional form (DATF) technique introduced by Liu et al. and develop an input difference selection strategy. Next, we present a condition imposing algorithm to handle the complicated conditions. We revisit previous research and show that our algorithm can control differential propagation over the same number of rounds (0–15 rounds) using just 21 conditions, a significant reduction from the 98 conditions required by prior methods. Finally, we apply the conditional differential attack to 51-round Atom, enabling the recovery of 3 key bits with data and time complexities of 2^29. The distinguisher of 51-round Atom has been thoroughly verified through practical experiments conducted on a 4.20GHz AMD 7950X3D CPU. To the best of our knowledge, this is the best result of conditional differential attack on round-reduced Atom reported in the publicly available literature.
Cite this paper
Lu, X., Tan, Z., & Xin, H. (2025). Conditional Differential Attack on Lightweight Stream Cipher Atom. https://doi.org/10.1109/icncis67521.2025.11296074
Lu, Xiaojuan, et al. “Conditional Differential Attack on Lightweight Stream Cipher Atom.” 2025, pp. 76–79, https://doi.org/10.1109/icncis67521.2025.11296074.
Lu, Xiaojuan, Zixin Tan, and Hongcai Xin. 2025. “Conditional Differential Attack on Lightweight Stream Cipher Atom.” https://doi.org/10.1109/icncis67521.2025.11296074.
Lu, X., Tan, Z. and Xin, H. (2025) ‘Conditional Differential Attack on Lightweight Stream Cipher Atom’. Available at: https://doi.org/10.1109/icncis67521.2025.11296074.
@article{lu2025conditional,
title = {{Conditional Differential Attack on Lightweight Stream Cipher Atom}},
author = {Lu, Xiaojuan and Tan, Zixin and Xin, Hongcai},
pages = {76--79},
year = {2025},
doi = {10.1109/icncis67521.2025.11296074}
}Made from the index record. Check names, capitalisation and page numbers against the paper. Need another style? AI for Research has over 10,000.