用户自助组件，使得最终用户能够执行某些安全管理任务，而无需管理监督，如周期性地更改密码。
User self-care component, to enable end users to carry out certain security administrative tasks without administrative supervision, such as periodically changing a password.
利用混沌映射具有对初值的敏感性和遍历性等特点，采用多次迭代的一维均衡混沌映射构造了一种非周期、均匀分布的多表代换密码。
Utilize the sensitivity and ergodic characteristic of the chaos map, a non-periodic and uniformity distributing multi-chart substitution is designed with multi-iterative equilibrium chaos map.
DES应用于序列密码体制，其周期性问题没有一般的结论。
There are not any general conclusions about periodicity of DES when itis used in stream cipher system.
DES应用于序列密码体制，其周期性问题没有一般的结论。
There are not any general conclusions about periodicity of DES when itis used in stream cipher system.
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