Cryptanalysis of enhanced MORE

Rok, strany: 2019, 163 - 178

Fully homomorphic encryption (FHE) has been among the most popular research topics of the last decade. While the bootstrapping-based, public key cryptosystems that follow Gentry's original design are getting more and more efficient, their performance is still far from being practical. This leads to several attempts to construct \textit{symmetric} FHE schemes that would not be as inefficient as their public key counterparts. Unfortunately, most such schemes were also based on (randomized) linear transformations, and shown to be completely insecure. One such broken scheme was the Matrix Operation for Randomization and Encryption (MORE). In a recent paper, Hariss, Noura and Samhat propose Enhanced MORE, which is supposed to improve over MORE's weaknesses. We analyze Enhanced MORE, discuss why it does not improve over MORE, and show that it is even less secure by presenting a highly efficient ciphertext-only decryption attack. We implement the attack and confirm its correctness.

ISO 690:

Vizár, D., Vaudenay, S. 2019. Cryptanalysis of enhanced MORE. In Tatra Mountains Mathematical Publications, vol. 73, no.1, pp. 163-178. 1210-3195. DOI: https://doi.org/10.2478/tmmp-2019-0012

APA:

Vizár, D., Vaudenay, S. (2019). Cryptanalysis of enhanced MORE. Tatra Mountains Mathematical Publications, 73(1), 163-178. 1210-3195. DOI: https://doi.org/10.2478/tmmp-2019-0012

Vydavateľ: Mathematical Institute, Slovak Academy of Sciences, Bratislava

© 2019 Mathematical Institute, Slovak Academy of Sciences. Licensed under the Creative Commons Attribution-NC-ND 4.0 International Public License.