# Predicting Outcomes of ElimLin Attack on Lightweight Block Cipher Simon

### Nicolas T. Courtois, Pouyan Sepehrdad, Guangyan Song, Iason Papapanagiotakis-Bousy

#### Abstract

There are two major families in cryptanalytic attacks on symmetric ciphers: statistical attacks and algebraic attacks. In this position paper we argue that algebraic cryptanalysis has not yet been developed properly due to the weakness of the theory which has substantial difficulty to prove most basic results on the number of linearly independent equations in algebraic attacks. Consequently most authors present a restricted range of attacks which are shown experimentally to work with their computer but refrain from claiming results which would work on a larger computer but have not yet been tested. For example in recent 2015 work of Raddum we discover that (experimentally) ElimLin attack breaks up to 16 rounds of Simon block cipher however it is hard to know what happens for 17 rounds. In this paper we argue that one CAN predict and model the behavior of such attacks and evaluate complexity of the attacks which we cannot yet execute. To the best of our knowledge this has never been done before.

#### References

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#### Paper Citation

#### in Harvard Style

Courtois N., Sepehrdad P., Song G. and Papapanagiotakis-Bousy I. (2016). **Predicting Outcomes of ElimLin Attack on Lightweight Block Cipher Simon** . In *Proceedings of the 13th International Joint Conference on e-Business and Telecommunications - Volume 4: SECRYPT, (ICETE 2016)* ISBN 978-989-758-196-0, pages 465-470. DOI: 10.5220/0005999504650470

#### in Bibtex Style

@conference{secrypt16,

author={Nicolas T. Courtois and Pouyan Sepehrdad and Guangyan Song and Iason Papapanagiotakis-Bousy},

title={Predicting Outcomes of ElimLin Attack on Lightweight Block Cipher Simon},

booktitle={Proceedings of the 13th International Joint Conference on e-Business and Telecommunications - Volume 4: SECRYPT, (ICETE 2016)},

year={2016},

pages={465-470},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0005999504650470},

isbn={978-989-758-196-0},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the 13th International Joint Conference on e-Business and Telecommunications - Volume 4: SECRYPT, (ICETE 2016)

TI - Predicting Outcomes of ElimLin Attack on Lightweight Block Cipher Simon

SN - 978-989-758-196-0

AU - Courtois N.

AU - Sepehrdad P.

AU - Song G.

AU - Papapanagiotakis-Bousy I.

PY - 2016

SP - 465

EP - 470

DO - 10.5220/0005999504650470