利用RSA对称算法实现文件加密，密钥512位，比较安全。但不是特别安全。因为推荐2048位的密钥目前是很安全的。-use RSA asymmetric encryption algorithm document, the key 512, relatively safe. But it is not particularly safe. Since 2048 recommended the key now is very safe.

实现RSA加密算法的c++源代码-achieve RSA encryption algorithm source code c