Windows Phone Encrypting/Decrypting the Data for Security

in this Blog we are using The Data Protection APIs.

1) Make a project with the name EncryptionAndDecryption and copy the given layout to MainPage.xaml


<phone:PhoneApplicationPage
    x:Class="EncryptionAndDecryption.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="Encryption And Decryption" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="Data Security" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <TextBlock  Text="enterdata" />
            <TextBox  Name="textBlock1" VerticalContentAlignment="Top" VerticalAlignment="Top" Margin="-3,44,3,0" />
            <Button Click="Encrypt_Click"  Name="Encrypt" Content="Encrypt" VerticalAlignment="Center" Height="83" Margin="0,240,0,284" />
            <Button Click="Decrypt_Click" Name="Decrypt" Content="Decrypt" VerticalAlignment="Bottom" Height="82" Margin="0,0,0,153" VerticalContentAlignment="Bottom" />
        </Grid>
    </Grid>

    <!--Sample code showing usage of ApplicationBar-->
    <!--<phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>
            <shell:ApplicationBar.MenuItems>
                <shell:ApplicationBarMenuItem Text="MenuItem 1"/>
                <shell:ApplicationBarMenuItem Text="MenuItem 2"/>
            </shell:ApplicationBar.MenuItems>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>-->

</phone:PhoneApplicationPage>

2) now copy the following code to MainPage.xaml.cs


using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;
using System.IO;
using System.IO.IsolatedStorage;
using System.Text;
using System.Security.Cryptography;


namespace EncryptionAndDecryption
{
    public partial class MainPage : PhoneApplicationPage
    {   String strFilePath="jitesh";
        // Constructor
        public MainPage()
        {
            InitializeComponent();
        }

        private void Encrypt_Click(object sender, RoutedEventArgs e)
        {
            byte[] PinByte = Encoding.UTF8.GetBytes(textBlock1.Text);
            byte[] ProtectedPinByte = ProtectedData.Protect(PinByte, null);
            this.Writedata(ProtectedPinByte);
            textBlock1.Text = "";
            MessageBox.Show("Encrypted the Pin!!!");
        }
        private void Writedata(byte[] pinData)
        {
            IsolatedStorageFile ISfile =
            IsolatedStorageFile.GetUserStoreForApplication();
            IsolatedStorageFileStream swIS = new IsolatedStorageFileStream(strFilePath,
            System.IO.FileMode.Create, System.IO.FileAccess.Write, ISfile);
            Stream writer = new StreamWriter(swIS).BaseStream;
            writer.Write(pinData, 0, pinData.Length);
            writer.Close();
            swIS.Close();

        }
        private void Decrypt_Click(object sender, RoutedEventArgs e)
        {
            byte[] ProtectedPinByte = this.ReadPinFromFile();
            byte[] PinByte = ProtectedData.Unprotect(ProtectedPinByte, null);
            textBlock1.Text = Encoding.UTF8.GetString(PinByte, 0, PinByte.Length);
        }
        private byte[] ReadPinFromFile()
        {
            IsolatedStorageFile ISfile =
            IsolatedStorageFile.GetUserStoreForApplication();
            IsolatedStorageFileStream rsIS = new IsolatedStorageFileStream(strFilePath,
            System.IO.FileMode.Open, FileAccess.Read, ISfile);
            Stream reader = new StreamReader(rsIS).BaseStream;
            byte[] pinArray = new byte[reader.Length];
            reader.Read(pinArray, 0, pinArray.Length);
            reader.Close();
            rsIS.Close();
            return pinArray;
        }
    }
}