Speck (cipher)

Speck
3 rounds of Speck with 2-word key schedule
General
DesignersRay Beaulieu, Douglas Shors, Jason Smith, Stefan Treatman-Clark, Bryan Weeks, Louis Wingers NSA
First published2013
Related toSimon, Threefish
Cipher detail
Key sizes64, 72, 96, 128, 144, 192 or 256 bits
Block sizes32, 48, 64, 96 or 128 bits
StructureARX
Rounds22–34 (depending on block and key size)
Speed2.6 cpb (5.7 without SSE) on Intel Xeon 5640 (Speck128/128)
Best public cryptanalysis
No attacks are known on the full ciphers, but reduced-round versions have been attacked. Differential cryptanalysis can break about 70–75% of the rounds of most variants slightly faster than brute-force;[1][2] see #Cryptanalysis.

Speck is a family of lightweight block ciphers publicly released by the National Security Agency (NSA) in June 2013.[3] Speck has been optimized for performance in software implementations, while its sister algorithm, Simon, has been optimized for hardware implementations. Speck is an add–rotate–xor (ARX) cipher.

The NSA began working on the Simon and Speck ciphers in 2011. The agency anticipated some agencies in the US federal government would need a cipher that would operate well on a diverse collection of Internet of Things devices while maintaining an acceptable level of security.[4]

  1. ^ Ling, Song; Huang, Zhangjie; Yang, Qianqian (2016-06-30). "Automatic Differential Analysis of ARX Block Ciphers with Application to SPECK and LEA" (PDF). Retrieved 2018-05-06.
  2. ^ Lee, HoChang; Kim, Seojin; Kang, HyungChul; Hong, Deukjo; Sung, Jaechul; Hong, Seokhie (February 2018). "Calculating the Approximate Probability of Differentials for ARX-Based Cipher Using SAT Solver". Journal of the Korea Institute of Information Security and Cryptology (in Korean). 28 (1): 15–24. doi:10.13089/JKIISC.2018.28.1.15.
  3. ^ Beaulieu, Ray; Shors, Douglas; Smith, Jason; Treatman-Clark, Stefan; Weeks, Bryan; Wingers, Louis (2013-06-19). "The SIMON and SPECK Families of Lightweight Block Ciphers". Retrieved 2016-09-20.
  4. ^ Beaulieu, Ray; Shors, Douglas; Smith, Jason; Treatman-Clark, Stefan; Weeks, Bryan; Winger, Louis (2015-07-09). "Simon and Speck: Block Ciphers for the Internet of Things" (PDF). Retrieved 2017-11-23.