说明：  自己辛辛苦苦做出来的软件轻轻松松被人盗版了，就像叶圣陶先生的小说《多了三五斗》中丰收 了却高兴不起来的农民一样——闭上眼睛就是天黑。所以，加密是一个软件工程师保护自己辛勤劳动成果的必备技术(开源软件和有其它盈利模式的软件除外)。
(Hard to do it yourself easily be pirated software, like the novel by Ye more bucket 35 in the harvest was not happy farmers like- close your eyes is dark. Therefore, encryption is a software engineer working hard to protect their essential technical achievements (except open source software and other software profit model).)