public string Encrypt(string value) { System.Security.Cryptography.DES des = System.Security.Cryptography.DES.Create(); byte[] tmp = Encoding.UTF8.GetBytes(value); Byte[] encryptoData; ICryptoTransform encryptor = des.CreateEncryptor(key, iv); using (MemoryStream memoryStream = new MemoryStream()) { using (var cs = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write)) { using (StreamWriter writer = new StreamWriter(cs)) { writer.Write(value); writer.Flush(); } } encryptoData = memoryStream.ToArray(); } des.Clear(); return(Convert.ToBase64String(encryptoData)); }