It is based on the data encryption standard algorithm with variations intended to discourage use of hardware implementations of a key search 它基于数据加密标准（ data encryption standard ）算法，并具有一些用来禁用密钥搜索的硬件实现的变种。
2.
The establishment of classification database is to manage easily the classification information and to provide necessary data for multi - way search . the establishment of key databank is to provide necessary data and information for dichotomous key search 分类数据库的建立是为了使分类资料的管理更加方便，也为多途径检索提供必需的资料；检索表数据库的建立则是为二项式检索提供必需的数据、信息。
