Paper 2013/543

Cryptanalysis of the SIMON Family of Block Ciphers

Hoda A. Alkhzaimi and Martin M. Lauridsen


Recently, the U.S National Security Agency has published the specifications of two families of lightweight block ciphers, SIMON and SPECK, in ePrint report 2013/404. The ciphers are developed with optimization towards both hardware and software in mind. While the specification paper discusses design requirements and performance of the presented lightweight ciphers thoroughly, no security assessment is given. This paper is a move towards filling that cryptanalysis gap for the SIMON family of ciphers. We present a series of observations on the presented construction that, in some cases, yield attacks, while in other cases may provide basis of further analysis by the cryptographic community. Specifically, we obtain attacks using classical- as well as truncated differentials. In the former case, we show how the smallest version of SIMON, Simon32/64, exhibits a strong differential effect.

Available format(s)
Secret-key cryptography
Publication info
Preprint. MINOR revision.
lightweightblock cipherFeistelSIMONdifferential cryptanalysisimpossible differentialsrotational cryptanalysisweak keys
Contact author(s)
mmeh @ dtu dk
2013-08-30: received
Short URL
Creative Commons Attribution


      author = {Hoda A.  Alkhzaimi and Martin M.  Lauridsen},
      title = {Cryptanalysis of the SIMON Family of Block Ciphers},
      howpublished = {Cryptology ePrint Archive, Paper 2013/543},
      year = {2013},
      note = {\url{}},
      url = {}
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