Skip to main content

Cryptanalysis of SIMON Variants with Connections

  • Conference paper
  • First Online:
Radio Frequency Identification: Security and Privacy Issues (RFIDSec 2015)


SIMON is a family of 10 lightweight block ciphers published by Beaulieu et al. from the United States National Security Agency (NSA). A cipher in this family with \(K\)-bit key and \(N\)-bit block is called SIMON\({N}/{K}\). We present several linear characteristics for reduced-round SIMON32/64 that can be used for a key-recovery attack and extend them further to attack other variants of SIMON. Moreover, we provide results of key recovery analysis using several impossible differential characteristics starting from 14 out of 32 rounds for SIMON32/64 to 22 out of 72 rounds for SIMON128/256. In some cases the presented observations do not directly yield an attack, but provide a basis for further analysis for the specific SIMON variant. Finally, we exploit a connection between linear and differential characteristics for SIMON to construct linear characteristics for different variants of reduced-round SIMON. Our attacks extend to all variants of SIMON covering more rounds compared to any known results using linear cryptanalysis. We present a key recovery attack against SIMON128/256 which covers 35 out of 72 rounds with data complexity \(2^{123}\). We have implemented our attacks for small scale variants of SIMON and our experiments confirm the theoretical bias presented in this work.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
USD 39.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 54.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions


  1. Abed, F., List, E., Lucks, S., Wenzel, J.: Differential Cryptanalysis of Reduced-Round Simon. Cryptology ePrint Archive, Report 2013/526 (2013).

  2. Abed, F., List, E., Lucks, S., Wenzel, J.: Differential cryptanalysis of round-reduced Simon and Speck. In: Preproceedings of Fast Software Encryption (FSE 2014) (2014, to appear)

    Google Scholar 

  3. Alizadeh, J., Bagheri, N., Gauravaram, P., Kumar, A., Sanadhya, S.K.: Linear Cryptanalysis of Round Reduced SIMON. Cryptology ePrint Archive, Report 2013/663 (2013)

  4. Alkhzaimi, H.A., Lauridsen, M.M.: Cryptanalysis of the SIMON Family of Block Ciphers. Cryptology ePrint Archive, Report 2013/543 (2013).

  5. Beaulieu, R., Shors, D., Smith, J., Treatman-Clark, S., Weeks, B., Wingers, L.: The SIMON and SPECK Families of Lightweight Block Ciphers. Cryptology ePrint Archive, Report 2013/404 (2013).

  6. Biham, E., Biryukov, A., Shamir, A.: Miss in the middle attacks on IDEA and Khufu. In: Knudsen, L.R. (ed.) FSE 1999. LNCS, vol. 1636, p. 124. Springer, Heidelberg (1999)

    Google Scholar 

  7. Biham, E., Shamir, A.: Differential cryptanalysis of the full 16-round DES. In: Brickell, E.F. (ed.) CRYPTO 1992. LNCS, vol. 740, pp. 487–496. Springer, Heidelberg (1993)

    Google Scholar 

  8. Biryukov, A., Roy, A., Velichkov, V.: Differential analysis of block ciphers SIMON and SPECK. In: Preproceedings of Fast Software Encryption (FSE 2014) (2014, to appear)

    Google Scholar 

  9. Blondeau, C., Nyberg, K.: New links between differential and linear cryptanalysis. In: Johansson, T., Nguyen, P.Q. (eds.) EUROCRYPT 2013. LNCS, vol. 7881, pp. 388–404. Springer, Heidelberg (2013)

    Google Scholar 

  10. Bogdanov, A.A., Knudsen, L.R., Leander, G., Paar, C., Poschmann, A., Robshaw, M., Seurin, Y., Vikkelsoe, C.: PRESENT: an ultra-lightweight block cipher. In: Paillier, P., Verbauwhede, I. (eds.) CHES 2007. LNCS, vol. 4727, pp. 450–466. Springer, Heidelberg (2007)

    Google Scholar 

  11. Chabaud, F., Vaudenay, S.: Links between differential and linear cryptanalysis. In: De Santis, A. (ed.) EUROCRYPT 1994. LNCS, vol. 950, pp. 356–365. Springer, Heidelberg (1995)

    Google Scholar 

  12. Cho, J.Y., Hermelin, M., Nyberg, K.: A new technique for multidimensional linear cryptanalysis with applications on reduced round serpent. In: Lee, P.J., Cheon, J.H. (eds.) ICISC 2008. LNCS, vol. 5461, pp. 383–398. Springer, Heidelberg (2009)

    Google Scholar 

  13. ISO/IEC 29192–2. Information technology - Security techniques - Lightweight cryptography - Part 2: Block ciphers. Technical report, International Organization for Standardization

    Google Scholar 

  14. Nakahara Jr., J., Preneel, B., Vandewalle, J.: Linear cryptanalysis of reduced-round versions of the SAFER block cipher family. In: Schneier, B. (ed.) FSE 2000. LNCS, vol. 1978, p. 244. Springer, Heidelberg (2001)

    Google Scholar 

  15. Knudsen, L.R.: DEAL - A 128-bit Block Cipher (1998)

    Google Scholar 

  16. Li, T., Lim, T.-L.: RFID Anticounterfeiting: An Architectural Perspective (2008)

    Google Scholar 

  17. Matsui, M.: Linear cryptanalysis method for DES cipher. In: Helleseth, T. (ed.) EUROCRYPT 1993. LNCS, vol. 765, pp. 386–397. Springer, Heidelberg (1994)

    Google Scholar 

  18. Nyberg, K.: Linear Cryptanalysis. Icebreak 2013 (2013).

  19. Saarinen, M.-J.O., Engels, D.: A Do-It-All-Cipher for RFID: Design Requirements (Extended Abstract). Cryptology ePrint Archive, Report 2012/317 (2012).

  20. Shirai, T., Shibutani, K., Akishita, T., Moriai, S., Iwata, T.: The 128-bit blockcipher CLEFIA (extended abstract). In: Biryukov, A. (ed.) FSE 2007. LNCS, vol. 4593, pp. 181–195. Springer, Heidelberg (2007)

    Google Scholar 

  21. Tardy-Corfdir, A., Gilbert, H.: A known plaintext attack of FEAL-4 and FEAL-6. In: Feigenbaum, J. (ed.) CRYPTO 1991. LNCS, vol. 576, pp. 172–182. Springer, Heidelberg (1992)

    Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Hoda A. Alkhzaimi .

Editor information

Editors and Affiliations


A Addenda to Impossible Differentials Cryptanalysis

In this appendix, we provide an example on impossible differential for Simon32/64 in Fig. 3. A detailed description on the attack and its complexity analysis can be found in an extended version of this part, see [4].

Fig. 3.
figure 3

A 10-round impossible differential for Simon32/64. Tracing truncated output differences in respectively forward and backward directions give a contradiction on the right half truncated mask after 5 rounds, where a 0 overlaps a 1.

B Experimental Results of Linear Cryptanalysis for SIMON32/64

We evaluated the theoretical results presented in Eq. 11 for 11-round SIMON32/64 experimentally. Table 7 presents the results. It shows that experimental results justify the theory and the bias of the presented path is not less than \(2^{-16}\).

Table 7. Experimental results for the linear characteristic of 11-round SIMON32/64 of Eq. 11. \(P_n\) is the number of known plaintexts; \(C_n\) is the number of plaintext/ciphertext pairs that satisfy Eq. 11; \(p = 1/2 + \epsilon \) is the probability that Eq. 11 holds.

C Sequences of Approximation Used Through Driving the Linear Characteristic of Each Variant of SIMON

In Table 8 we give the propagation of our linear characteristics for SIMON32/64.

Table 8. Sequences of approximation for SIMON32/64. \(\mathcal{A}_L\) and \(\mathcal{A}_R\) denote the active bits in the left and right side respectively and App. denotes the approximation used for the corresponding bit(s) of \(\mathcal{A}_R\).

Rights and permissions

Reprints and permissions

Copyright information

© 2014 Springer International Publishing Switzerland

About this paper

Cite this paper

Alizadeh, J. et al. (2014). Cryptanalysis of SIMON Variants with Connections. In: Saxena, N., Sadeghi, AR. (eds) Radio Frequency Identification: Security and Privacy Issues. RFIDSec 2015. Lecture Notes in Computer Science(), vol 8651. Springer, Cham.

Download citation

  • DOI:

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-319-13065-1

  • Online ISBN: 978-3-319-13066-8

  • eBook Packages: Computer ScienceComputer Science (R0)

Publish with us

Policies and ethics