In:
The Computer Journal, Oxford University Press (OUP), Vol. 63, No. 12 ( 2020-12-17), p. 1859-1870
Abstract:
In ASIACRYPT 2014, Jean et al. proposed the authentication encryption scheme Deoxys, which is one of the third-round candidates in CAESAR competition. Its internal block cipher is called Deoxys-BC that adopts the tweakey frame. Deoxys-BC has two versions of the tweakey size that are 256 bits and 384 bits, denoted by Deoxys-BC-256 and Deoxys-BC-384, respectively. In this paper, we revaluate the security of Deoxys-BC-256 against the meet-in-the-middle attack to obtain some new results. First, we append one round at the top and two rounds at the bottom of a 6-round distinguisher to form a 9-round truncated differential path with the probability of $2^{-144}$. Based on it, the adversary can attack 9-round Deoxys-BC-256 with $2^{108}$ chosen plaintext-tweaks, $2^{113.6}$ encryptions and $2^{102}$ blocks. Second, we construct a new 6.5-round distinguisher to form 10-round attacking path with the probability of $2^{-152}$. On the basis of it, the adversary could attack 10-round Deoxys-BC-256 with $2^{115}$ chosen plaintext-tweaks, $2^{171}$ encryptions and $2^{152}$ blocks. These two attacks improve the previous cryptanalytic results on reduced-round Deoxys-BC-256 against the meet-in-the-middle attack.
Type of Medium:
Online Resource
ISSN:
0010-4620
,
1460-2067
DOI:
10.1093/comjnl/bxaa028
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2020
detail.hit.zdb_id:
1477172-X
