Paper 2025/2070

MIFA: An MILP-based Framework for Improving Differential Fault Attacks

Insung Kim, Korea University

Sunyeop Kim, Korea University, Nanyang Technological University

Byoungjin Seok, Hansung University

Deukjo Hong, Jeonbuk National University

Jaechul Sung, University of Seoul

Seokhie Hong, SmartM2M

Sangjin Lee, Korea University

Dongjae Lee, Kangwon National University

Abstract

At ASIACRYPT 2021, Baksi et al. introduced DEFAULT, a block cipher designed to algorithmically resist Differential Fault Attack (DFA), claiming 64-bit DFA security regardless of the number of injected faults. At EUROCRYPT 2022, Nageler et al. demonstrated that DEFAULT's claimed DFA resistance can be broken by applying an information-combining technique. More recently, at ASIACRYPT 2024, Jana et al. improved DFA by searching for differential trails with a single solution. They showed that, for DEFAULT with a simple key schedule, injecting five faults at the fifth-to-last round reduces the key space to one, and for BAKSHEESH, injecting twelve faults at the third-to-last round achieves the same result. In this paper, we propose a new DFA framework that utilizes a Mixed-Integer Linear Programming (MILP) solver. This framework makes it possible to attack deeper rounds than previously achieved, reducing the number of fault injections required for key recovery. Furthermore, we present a method to determine the most efficient fault injection bit positions by systematically analyzing the input differences from all possible single bit-flip faults, thereby further reducing the required number of faults. This systematic analysis has the significant advantage of allowing us to theoretically calculate the required number of faults. Applying our framework, for DEFAULT, injecting three faults at the sixth-to-last round and two faults at the seventh- and eighth-to-last rounds reduces the key space to one.

@misc{cryptoeprint:2025/2070,
      author = {Hanbeom Shin and Insung Kim and Sunyeop Kim and Byoungjin Seok and Deukjo Hong and Jaechul Sung and Seokhie Hong and Sangjin Lee and Dongjae Lee},
      title = {{MIFA}: An {MILP}-based Framework for Improving Differential Fault Attacks},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/2070},
      year = {2025},
      url = {https://eprint.iacr.org/2025/2070}
}