双向加密

(string strSource)方法用来对比比较重要的信息进行加密
Dencrypting(string source)方法将已加密的信息进行解密

using System.Security.Cryptography;
using System.IO;
using System.Text;

public static string Encrypting(string strSource)
    {
        byte[] bytln = System.Text.Encoding.Default.GetBytes(strSource);
        byte[] iv = {102,16,93,156,78,4,218,32 };//定义偏移量
        byte[] key = {55,103,246,79,36,99,167,3 };//定义**
        //实例DES加密类
        DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
        mobjCryptoService.Key = iv;
        mobjCryptoService.IV = key;
        ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
        //实例MemoryStream流加密文件
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        CryptoStream cs = new CryptoStream(ms,encrypto ,CryptoStreamMode.Write );
        cs.Write(bytln ,0,bytln.Length );
        cs.FlushFinalBlock();
        return System.Convert.ToBase64String(ms.ToArray ());

    }

    public static string Dencrypting(string source)
    {
        try
        {
            //将解密字符串转成字节数组
            byte[] bytln = System.Convert.FromBase64String(source);
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定义偏移量
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定义**        
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;        
            //实例流进行解密
            System.IO.MemoryStream ms = new System.IO.MemoryStream(bytln ,0,bytln .Length );
            ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
            StreamReader strd = new StreamReader(cs, Encoding.Default);
            return strd.ReadToEnd();
        }
        catch (Exception ex)
        {
            throw new Exception("在文件解密的时候出现错误"+ex.Message );
        }
    }