A taxonomy was developed by Axelsson to define the space of intrusion detection technology and classify IDSs. The taxonomy categorizes IDSs by their detection principle and their operational aspects. The two main categories of detection principle

以C++语言在微机上实现了美国数据加密标准DES。可随微机软盘任意路径下的任何文件，加密，加密文件可在软、硬盘任何目录下或在网络中传送；另一方面可对软、硬盘中的任何文件进行解密，解密后的文件除在末尾多出几个空格符外与原文件完全相同，绝不影响EXE文件，COM文件或数据库文件的使用。密钥有加密者在键盘输入8个字符。-In c++ language microcomputer to U.S. data encryption standard DES. With the computer floppy