In order to construct new perfect nonlinear functions, investigating the preimage distributionsof perfect nonlinear functions is very important.
为构造新的完全非线性函数,研究完全非线性函数的原像分布特征具有十分重要的作用。
Secondly, the construction of the initial structure and the skipping steps is proposed and the technology and method of preimage attack of MD5 is analyzed in detail.
其次通过介绍初始结构和过渡结构的构建,详细解析了对MD5进行原像攻击的技术和方法;
The preimage entropies in the dynamical systems are investigated. The correct proof of the result about preimage branch entropy:"graph mapping has zero preimage branch entropy"is given.