11轮3D分组密码算法的中间相遇攻击

针对3D分组密码算法的安全性分析,对该算法抵抗中间相遇攻击的能力进行了评估。基于3D算法的基本结构及S盒的差分性质,减少了在构造多重集时所需的猜测字节数,从而构建了新的6轮3D算法中间相遇区分器。然后,将区分器向前扩展2轮,向后扩展3轮,得到11轮3D算法中间相遇攻击。实验结果表明:构建区分器时所需猜测的字节数为42 B,攻击时所需的数据复杂度约为2⁴⁹⁷个选择明文,时间复杂度约为2^325.3次11轮3D算法加密,存储复杂度约为2³⁴² B。新攻击表明11轮3D算法对中间相遇攻击是不免疫的。

Meet-in-the-middle attack on 11-round reduced 3D block cipher

Focusing on the safety analysis of the 3D block cipher, a new method on this algorithm against the meet-in-the-middle attack was proposed. Based on the structure of the 3D algorithm and the differential properties of the S-box, the research reduced the number of required bytes during structuring the multiple sets in this attack and constructed a new 6-round meet-in-the-middle distinguisher. According to extending the distinguisher 2-round forward and 3-round backward, an 11-round meet-in-the-middle attack of the 3D algorithm was finally achieved. The experimental results show that:the number of required bytes on constructed the distinguisher is 42, the attack requires a data complexity of about 2⁴⁹⁷ chosen plaintexts, a time complexity of about 2^325.3 11-round 3D algorithm encryption and a memory complexity of about 2³⁴² bytes. The new attack shows that the 11-round of the 3D algorithm is not immune to the meet-in-the-middle attack.