Paper 2019/727

Iterative Differential Characteristic of TRIFLE-BC

Fukang Liu and Takanori Isobe


TRIFLE is a Round 1 candidate of the NIST Lightweight Cryptography Standardization process. In this paper, we present an interesting 1-round iterative differential characteristic of the underlying block cipher TRIFLE-BC used in TRIFLE, which holds with probability of $2^{-3}$. Consequently, it allows to mount distinguishing attack on TRIFLE-BC for up to 43 (out of 50) rounds with data complexity $2^{124}$ and time complexity $2^{124}$. Most importantly, with such an iterative differential characteristic, the forgery attack on TRIFLE can reach up to 21 (out of 50) rounds with data complexity $2^{63}$ and time complexity $2^{63}$. Finally, to achieve key recovery attack on reduced TRIFLE, we construct a differential characteristic covering three blocks by carefully choosing the positions of the iterative differential characteristic. As a result, we can mount key-recovery attack on TRIFLE for up to 11 rounds with data complexity $2^{63}$ and time complexity $2^{104}$. Although the result in this paper cannot threaten the security margin of TRIFLE, we hope it can help further understand the security of TRIFLE.

Note: Correct some editorial mistakes.

Available format(s)
Secret-key cryptography
Publication info
Published elsewhere. MINOR revision.SAC 2019
AEADTRIFLEdifferential attackdistinguisherforgery
Contact author(s)
liufukangs @ 163 com
takanori isobe @ ai u-hyogo ac jp
2019-07-09: revised
2019-06-20: received
See all versions
Short URL
Creative Commons Attribution


      author = {Fukang Liu and Takanori Isobe},
      title = {Iterative Differential Characteristic of TRIFLE-BC},
      howpublished = {Cryptology ePrint Archive, Paper 2019/727},
      year = {2019},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.