CAJ | 학술논문

FOX 是基于 Mediacrypt 公司的需求而设计的系列分组密码。为进一步评估 FOX 密码的安全性，主要研究 FOX 密码抗中间相遇攻击的能力，根据其加密算法的结构，给出 FOX64的3轮和4轮中间相遇区分器，以及 FOX128的3轮中间相遇区分器。通过分别在以上区分器后加适当的轮数，对4到8轮的 FOX64和4、5轮的 FOX128进行中间相遇攻击，并给出攻击结果。结果证明了8轮 FOX64/256是不安全的。同时表明，5轮 FOX64/128、7轮 FOX64/192、8轮 FOX64/256和5轮 FOX128/256均不能抵抗中间相遇攻击。
FOX 시기우 Mediacrypt 공사적수구이설계적계렬분조밀마。위진일보평고 FOX 밀마적안전성，주요연구 FOX 밀마항중간상우공격적능력，근거기가밀산법적결구，급출 FOX64적3륜화4륜중간상우구분기，이급 FOX128적3륜중간상우구분기。통과분별재이상구분기후가괄당적륜수，대4도8륜적 FOX64화4、5륜적 FOX128진행중간상우공격，병급출공격결과。결과증명료8륜 FOX64/256시불안전적。동시표명，5륜 FOX64/128、7륜 FOX64/192、8륜 FOX64/256화5륜 FOX128/256균불능저항중간상우공격。
FOX is a family of block ciphers,which was designed according to the need of Mediacrypt.In this paper we mainly study the ability of FOX cipher in resisting the meet-in-the-middle attack in order to further evaluate its security.Based on the structure of FOX,3-round and 4-round meet-in-the-middle distinguishers of FOX64 are given.3-round meet-in-the-middle distinguishers of FOX128 are given as well.By adding proper rounds to the above distinguishers,the meet-in-the-middle attacks are applied to 4 to 8-round FOX64,and to 4 and 5-round FOX128,and the attacking results are presented.These results prove that 8-round FOX64 /256 is insecure.Meanwhile,it is demon-strated that 5-round FOX64 /128,7-round FOX64 /192,8-round FOX64 /256 and 5-round FOX128 /256 are all not immune to meet-in-the-middle attack.