using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Security.Cryptography;using System.IO; namespace ConsoleApplication1{ class Program { static string encryptKey = "Oyea"; //定义密钥 #region 加密字符串 /// <summary> /// 加密字符串 /// </summary> /// <param name="str">要加密的字符串</param> /// <returns>加密后的字符串</returns> static string Encrypt(string str) { DESCryptoServiceProvider descsp = new DESCryptoServiceProvider(); //实例化加/解密类对象 byte[] key = Encoding.Unicode.GetBytes(encryptKey); //定义字节数组，用来存储密钥 byte[] data = Encoding.Unicode.GetBytes(str);//定义字节数组，用来存储要加密的字符串 MemoryStream MStream = new MemoryStream(); //实例化内存流对象 //使用内存流实例化加密流对象 CryptoStream CStream = new CryptoStream(MStream, descsp.CreateEncryptor(key, key), CryptoStreamMode.Write); CStream.Write(data, 0, data.Length); //向加密流中写入数据 CStream.FlushFinalBlock(); //释放加密流 return Convert.ToBase64String(MStream.ToArray());//返回加密后的字符串 } #endregion #region 解密字符串 /// <summary> /// 解密字符串 /// </summary> /// <param name="str">要解密的字符串</param> /// <returns>解密后的字符串</returns> static string Decrypt(string str) { DESCryptoServiceProvider descsp = new DESCryptoServiceProvider(); //实例化加/解密类对象 byte[] key = Encoding.Unicode.GetBytes(encryptKey); //定义字节数组，用来存储密钥 byte[] data = Convert.FromBase64String(str);//定义字节数组，用来存储要解密的字符串 MemoryStream MStream = new MemoryStream(); //实例化内存流对象 //使用内存流实例化解密流对象 CryptoStream CStream = new CryptoStream(MStream, descsp.CreateDecryptor(key, key), CryptoStreamMode.Write); CStream.Write(data, 0, data.Length); //向解密流中写入数据 CStream.FlushFinalBlock(); //释放解密流 return Encoding.Unicode.GetString(MStream.ToArray()); //返回解密后的字符串 } #endregion static void Main(string[] args) { Console.Write("请输入要加密的字符串："); //提示输入字符串 Console.WriteLine(); //换行输入 string str = Console.ReadLine(); //记录输入的字符串 string strNew = Encrypt(str); //加密字符串 Console.WriteLine("加密后的字符串：" + strNew); //输出加密后的字符串 Console.WriteLine("解密后的字符串：" + Decrypt(strNew)); //解密字符串并输出 Console.ReadLine(); } }}原文：http://www.cnblogs.com/dong-blog/p/5823562.html