Improved Key Recovery Attacks on Reduced-Round AES with Practical Data and Memory Complexities

  • Achiya Bar-On
  • Orr DunkelmanEmail author
  • Nathan Keller
  • Eyal Ronen
  • Adi Shamir
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10992)


Determining the security of AES is a central problem in cryptanalysis, but progress in this area had been slow and only a handful of cryptanalytic techniques led to significant advancements. At Eurocrypt 2017 Grassi et al. presented a novel type of distinguisher for AES-like structures, but so far all the published attacks which were based on this distinguisher were inferior to previously known attacks in their complexity. In this paper we combine the technique of Grassi et al. with several other techniques to obtain the best known key recovery attack on 5-round AES in the single-key model, reducing its overall complexity from about \(2^{32}\) to about \(2^{22.5}\). Extending our techniques to 7-round AES, we obtain the best known attacks on AES-192 which use practical amounts of data and memory, breaking the record for such attacks which was obtained 18 years ago by the classical Square attack.



The research of Achiya Bar-On and of Nathan Keller was supported by the European Research Council under the ERC starting grant agreement n. 757731 (LightCrypt) and by the BIU Center for Research in Applied Cryptography and Cyber Security in conjunction with the Israel National Cyber Bureau in the Prime Minister’s Office. The research of Orr Dunkelman was supported by the Israel Ministry of Science and Technology.


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Copyright information

© International Association for Cryptologic Research 2018

Authors and Affiliations

  • Achiya Bar-On
    • 1
  • Orr Dunkelman
    • 2
    Email author
  • Nathan Keller
    • 1
  • Eyal Ronen
    • 3
  • Adi Shamir
    • 3
  1. 1.Department of MathematicsBar-Ilan UniversityRamat GanIsrael
  2. 2.Computer Science DepartmentUniversity of HaifaHaifaIsrael
  3. 3.Computer Science DepartmentThe Weizmann InstituteRehovotIsrael

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