public class DESHelper{#region 3des加密/// <summary>/// 3des ecb模式加密/// </summary>/// <param name="aStrString">待加密的字符串</param>/// <param name="aStrKey">密钥</param>/// <param name="iv">加密矢量：只有在CBC解密模式下才适用</param>/// <param name="mode">运算模式</param>/// <returns>加密后的字符串</returns>public static string Encrypt3Des(string aStrString, string aStrKey, CipherMode mode = CipherMode.ECB, string iv = "12345678"){try{var des = new TripleDESCryptoServiceProvider{Key = Encoding.UTF8.GetBytes(aStrKey),Mode = mode};if (mode == CipherMode.CBC){des.IV = Encoding.UTF8.GetBytes(iv);}var desEncrypt = des.CreateEncryptor();byte[] buffer = Encoding.UTF8.GetBytes(aStrString);buffer = Encoding.Convert(Encoding.GetEncoding("UTF-8"), Encoding.GetEncoding("GB2312"), buffer);return Convert.ToBase64String(desEncrypt.TransformFinalBlock(buffer, 0, buffer.Length));}catch (Exception e){return string.Empty;}}#endregion#region 3des解密/// <summary>/// des 解密/// </summary>/// <param name="aStrString">加密的字符串</param>/// <param name="aStrKey">密钥</param>/// <param name="iv">解密矢量：只有在CBC解密模式下才适用</param>/// <param name="mode">运算模式</param>/// <returns>解密的字符串</returns>public static string Decrypt3Des(string aStrString, string aStrKey, CipherMode mode = CipherMode.ECB, string iv = "12345678"){try{var des = new TripleDESCryptoServiceProvider{Key = Encoding.UTF8.GetBytes(aStrKey),Mode = mode,Padding = PaddingMode.PKCS7};if (mode == CipherMode.CBC){des.IV = Encoding.UTF8.GetBytes(iv);}var desDecrypt = des.CreateDecryptor();var result = "";byte[] buffer = Convert.FromBase64String(aStrString);result = Encoding.UTF8.GetString(desDecrypt.TransformFinalBlock(buffer, 0, buffer.Length));return result;}catch (Exception e){return string.Empty;}}#endregion}

测试：注意key字符长度为24

        static void Main(string[] args){//IVstring IV = "20160120";//KEYstring KEY = "012345678901234567891234";//data json stringstring dataJsonString = "TEST";Console.WriteLine("加密之前："+ dataJsonString);//3des 加密string Encrypt3Des = DESHelper.Encrypt3Des(dataJsonString, KEY, CipherMode.CBC, IV);Console.WriteLine("加密之后：" + Encrypt3Des);//3des 解密string Decrypt3Des = DESHelper.Decrypt3Des(Encrypt3Des, KEY, CipherMode.CBC, IV);Console.WriteLine("解密密之后：" + Decrypt3Des);Console.ReadKey();}