C# DES加密解密字符串

//名称空间  using  System;  using  System.Security.Cryptography;  using  System.IO;  using  System.Text;    /**/    /// <summary>    ///  DES算法描述简介：    ///  DES是Data Encryption Standard（数据加密标准）的缩写。它是由IBM公司研制的一种加密算法，    /// 美国国家标准局于1977年公布把它作为非机要部门使用的数据加密标准；    /// 它是一个分组加密算法，他以64位为分组对数据加密。    /// 同时DES也是一个对称算法：加密和解密用的是同一个算法。    /// 它的密匙长度是56位（因为每个第8 位都用作奇偶校验），    /// 密匙可以是任意的56位的数，而且可以任意时候改变．    /// </summary>    //默认密钥向量    private static byte[] Keys ={ 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };    /// <summary>       /// DES加密字符串       /// </summary>       /// <param name="encryptString">待加密的字符串</param>       /// <param name="encryptKey">加密密钥,要求为8位</param>       /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>     public static string EncryptDES(string encryptString, string encryptKey)    {        try        {            byte[] Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));            byte[] IV = Keys;            byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);            DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();            MemoryStream mStream = new MemoryStream();            CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(Key, IV), CryptoStreamMode.Write);            cStream.Write(inputByteArray, 0, inputByteArray.Length);            cStream.FlushFinalBlock();            return Convert.ToBase64String(mStream.ToArray());        }        catch        {            return encryptString;        }    }    /// <summary>       /// DES解密字符串       /// </summary>       /// <param name="decryptString">待解密的字符串</param>       /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>       /// <returns>解密成功返回解密后的字符串，失败返源串</returns>      public static string DescryptDES(string descryptString, string descryptKey)    {        try        {            byte[] Key = Encoding.UTF8.GetBytes(descryptKey.Substring(0,8));            byte[] IV = Keys;            byte[] inputByteArray = Convert.FromBase64String(descryptString);            DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();            MemoryStream mStream = new MemoryStream();            CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(Key, IV), CryptoStreamMode.Write);            cStream.Write(inputByteArray, 0, inputByteArray.Length);            cStream.FlushFinalBlock();            return Encoding.UTF8.GetString(mStream.ToArray());        }        catch        {            return descryptString;        }    }

实例:

    protected void Page_Load(object sender, EventArgs e)    {        Response.Write("加密字符:hello world!,密钥为:[e-mail]");        string str = EncryptDES("hello world!","[e-mail]");        Response.Write("DES加密:" + str);        Response.Write("DES解密:" + DescryptDES(str, "[e-mail]"));      }