1）用C\C++语言实现仿射变换（Affine）加/解密算法；2）用C\C++语言实现统计26个英文字母出现的频率的程序；3）利用仿射变换加/解密程序对一段较长的英文文章进行加密，再利用统计软件对明文和密文中字母出现的频率进行统计并作对比-1) with C \ C++ language affine transformation (Affine) encryption/decryption algorithm　2) with C \ C++ language and Statistics 26 English letters the frequency of the procedure　3) the use of affine transformation encryption/decryption process on a a longer article in English is encrypted, and then use statistical software plaintext and ciphertext letter appears in the statistics and compare the frequency