Paper 2015/231
A Related-Key Chosen-IV Distinguishing Attack on Full Sprout Stream Cipher
Yonglin Hao
Abstract
Sprout is a new lightweight stream cipher proposed at FSE 2015. According to its designers, Sprout can resist time-memory-data trade-off (TMDTO) attacks with small internal state size. However, we find a weakness in the updating functions of Sprout and propose a related-key chosen-IV distinguishing attacks on full Sprout. Under the related-key setting, our attacks enable the adversary to detect non-randomness on full 320-round Sprout with a practical complexity of $\tilde{O}(2^4)$ and find collisions in 256 output bits of full Sprout with a complexity of $\tilde{O}(2^7)$. Furthermore, when considering possible remedies, we find that only by modifying the updating functions and output function seems unlikely to equip Sprout with better resistance against this kind of distinguisher. Therefore, it is necessary for designers to give structural modifications.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint. MAJOR revision.
- Keywords
- stream cipherSproutdistinguishing attack
- Contact author(s)
- haoyl14 @ mails tsinghua edu cn
- History
- 2015-03-18: last of 4 revisions
- 2015-03-12: received
- See all versions
- Short URL
- https://ia.cr/2015/231
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2015/231,
author = {Yonglin Hao},
title = {A Related-Key Chosen-{IV} Distinguishing Attack on Full Sprout Stream Cipher},
howpublished = {Cryptology {ePrint} Archive, Paper 2015/231},
year = {2015},
url = {https://eprint.iacr.org/2015/231}
}
