Title of article :
Impossible Differential Cryptanalysis on Deoxys-BC-256
Author/Authors :
Mehrdad ، Alireza - Shahid Beheshti University , Moazami ، Farokhlagha - Shahid Beheshti University , Soleimany ، Hadi - Shahid Beheshti University
Pages :
13
From page :
93
To page :
105
Abstract :
Deoxys is a final-round candidate of the CAESAR competition. Deoxys is built upon an internal tweakable block cipher Deoxys-BC, where in addition to the plaintext and key, it takes an extra non-secret input called a tweak. This paper presents the first impossible differential cryptanalysis of Deoxys-BC-256 which is used in Deoxys as an internal tweakable block cipher. First, we find a 4.5-round ID characteristic by utilizing a miss-in-the-middle-approach. We then present several cryptanalysis based upon the 4.5 rounds distinguisher against round-reduced Deoxys-BC-256 in both single-key and related-key settings. Our contributions include impossible differential attacks on up to 8-round Deoxys-BC-256 in the single-key model. Our attack reaches 9 rounds in the related-key related-tweak model which has a slightly higher data complexity than the best previous results obtained by a related-key related-tweak rectangle attack presented at FSE 2018, but requires a lower memory complexity with an equal time complexity.
Keywords :
CAESAR Competition , Deoxys , BC , Impossible Differential , Cryptanalysis , Distinguisher
Journal title :
ISeCure, The ISC International Journal of Information Security
Serial Year :
2018
Journal title :
ISeCure, The ISC International Journal of Information Security
Record number :
2454684
Link To Document :
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